1 /* BFD back-end for linux flavored sparc a.out binaries.
2 Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, 2002,
3 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012
4 Free Software Foundation, Inc.
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 MA 02110-1301, USA. */
23 #define TARGET_PAGE_SIZE 4096
24 #define ZMAGIC_DISK_BLOCK_SIZE 1024
25 #define SEGMENT_SIZE TARGET_PAGE_SIZE
26 #define TEXT_START_ADDR 0x0
28 #define MACHTYPE_OK(mtype) ((mtype) == M_SPARC || (mtype) == M_UNKNOWN)
33 #include "aout/aout64.h"
34 #include "aout/stab_gnu.h"
36 #include "libaout.h" /* BFD a.out internal data structures */
38 #define DEFAULT_ARCH bfd_arch_sparc
39 /* Do not "beautify" the CONCAT* macro args. Traditional C will not
40 remove whitespace added here, and thus will fail to concatenate
42 #define MY(OP) CONCAT2 (sparclinux_,OP)
43 #define TARGETNAME "a.out-sparc-linux"
45 extern const bfd_target
MY(vec
);
47 /* We always generate QMAGIC files in preference to ZMAGIC files. It
48 would be possible to make this a linker option, if that ever
51 static void MY_final_link_callback
52 (bfd
*, file_ptr
*, file_ptr
*, file_ptr
*);
55 sparclinux_bfd_final_link (bfd
*abfd
, struct bfd_link_info
*info
)
57 obj_aout_subformat (abfd
) = q_magic_format
;
58 return NAME(aout
,final_link
) (abfd
, info
, MY_final_link_callback
);
61 #define MY_bfd_final_link sparclinux_bfd_final_link
63 /* Set the machine type correctly. */
66 sparclinux_write_object_contents (bfd
*abfd
)
68 struct external_exec exec_bytes
;
69 struct internal_exec
*execp
= exec_hdr (abfd
);
71 N_SET_MACHTYPE (*execp
, M_SPARC
);
73 obj_reloc_entry_size (abfd
) = RELOC_STD_SIZE
;
75 WRITE_HEADERS(abfd
, execp
);
80 #define MY_write_object_contents sparclinux_write_object_contents
81 /* Code to link against Linux a.out shared libraries. */
83 /* See if a symbol name is a reference to the global offset table. */
85 #ifndef GOT_REF_PREFIX
86 #define GOT_REF_PREFIX "__GOT_"
89 #define IS_GOT_SYM(name) (CONST_STRNEQ (name, GOT_REF_PREFIX))
91 /* See if a symbol name is a reference to the procedure linkage table. */
93 #ifndef PLT_REF_PREFIX
94 #define PLT_REF_PREFIX "__PLT_"
97 #define IS_PLT_SYM(name) (CONST_STRNEQ (name, PLT_REF_PREFIX))
99 /* This string is used to generate specialized error messages. */
102 #define NEEDS_SHRLIB "__NEEDS_SHRLIB_"
105 /* This special symbol is a set vector that contains a list of
106 pointers to fixup tables. It will be present in any dynamically
107 linked file. The linker generated fixup table should also be added
108 to the list, and it should always appear in the second slot (the
109 first one is a dummy with a magic number that is defined in
112 #ifndef SHARABLE_CONFLICTS
113 #define SHARABLE_CONFLICTS "__SHARABLE_CONFLICTS__"
116 /* We keep a list of fixups. The terminology is a bit strange, but
117 each fixup contains two 32 bit numbers. A regular fixup contains
118 an address and a pointer, and at runtime we should store the
119 address at the location pointed to by the pointer. A builtin fixup
120 contains two pointers, and we should read the address using one
121 pointer and store it at the location pointed to by the other
122 pointer. Builtin fixups come into play when we have duplicate
123 __GOT__ symbols for the same variable. The builtin fixup will copy
124 the GOT pointer from one over into the other. */
129 struct linux_link_hash_entry
*h
;
132 /* Nonzero if this is a jump instruction that needs to be fixed,
133 zero if this is just a pointer */
139 /* We don't need a special hash table entry structure, but we do need
140 to keep some information between linker passes, so we use a special
143 struct linux_link_hash_entry
145 struct aout_link_hash_entry root
;
148 struct linux_link_hash_table
150 struct aout_link_hash_table root
;
152 /* First dynamic object found in link. */
155 /* Number of fixups. */
158 /* Number of builtin fixups. */
159 size_t local_builtins
;
161 /* List of fixups. */
162 struct fixup
*fixup_list
;
166 /* Routine to create an entry in an Linux link hash table. */
168 static struct bfd_hash_entry
*
169 linux_link_hash_newfunc (struct bfd_hash_entry
*entry
,
170 struct bfd_hash_table
*table
,
173 struct linux_link_hash_entry
*ret
= (struct linux_link_hash_entry
*) entry
;
175 /* Allocate the structure if it has not already been allocated by a
177 if (ret
== (struct linux_link_hash_entry
*) NULL
)
178 ret
= ((struct linux_link_hash_entry
*)
179 bfd_hash_allocate (table
, sizeof (struct linux_link_hash_entry
)));
181 return (struct bfd_hash_entry
*) ret
;
183 /* Call the allocation method of the superclass. */
184 ret
= ((struct linux_link_hash_entry
*)
185 NAME(aout
,link_hash_newfunc
) ((struct bfd_hash_entry
*) ret
,
189 /* Set local fields; there aren't any. */
192 return (struct bfd_hash_entry
*) ret
;
195 /* Create a Linux link hash table. */
197 static struct bfd_link_hash_table
*
198 linux_link_hash_table_create (bfd
*abfd
)
200 struct linux_link_hash_table
*ret
;
201 bfd_size_type amt
= sizeof (struct linux_link_hash_table
);
203 ret
= (struct linux_link_hash_table
*) bfd_malloc (amt
);
204 if (ret
== (struct linux_link_hash_table
*) NULL
)
205 return (struct bfd_link_hash_table
*) NULL
;
206 if (!NAME(aout
,link_hash_table_init
) (&ret
->root
, abfd
,
207 linux_link_hash_newfunc
,
208 sizeof (struct linux_link_hash_entry
)))
211 return (struct bfd_link_hash_table
*) NULL
;
215 ret
->fixup_count
= 0;
216 ret
->local_builtins
= 0;
217 ret
->fixup_list
= NULL
;
219 return &ret
->root
.root
;
222 /* Look up an entry in a Linux link hash table. */
224 #define linux_link_hash_lookup(table, string, create, copy, follow) \
225 ((struct linux_link_hash_entry *) \
226 aout_link_hash_lookup (&(table)->root, (string), (create), (copy),\
229 /* Traverse a Linux link hash table. */
231 #define linux_link_hash_traverse(table, func, info) \
232 (aout_link_hash_traverse \
234 (bfd_boolean (*) (struct aout_link_hash_entry *, void *)) (func), \
237 /* Get the Linux link hash table from the info structure. This is
240 #define linux_hash_table(p) ((struct linux_link_hash_table *) ((p)->hash))
242 /* Store the information for a new fixup. */
244 static struct fixup
*
245 new_fixup (struct bfd_link_info
*info
,
246 struct linux_link_hash_entry
*h
,
252 f
= (struct fixup
*) bfd_hash_allocate (&info
->hash
->table
,
253 sizeof (struct fixup
));
256 f
->next
= linux_hash_table (info
)->fixup_list
;
257 linux_hash_table (info
)->fixup_list
= f
;
260 f
->builtin
= builtin
;
262 ++linux_hash_table (info
)->fixup_count
;
266 /* We come here once we realize that we are going to link to a shared
267 library. We need to create a special section that contains the
268 fixup table, and we ultimately need to add a pointer to this into
269 the set vector for SHARABLE_CONFLICTS. At this point we do not
270 know the size of the section, but that's OK - we just need to
271 create it for now. */
274 linux_link_create_dynamic_sections (bfd
*abfd
,
275 struct bfd_link_info
*info ATTRIBUTE_UNUSED
)
280 /* Note that we set the SEC_IN_MEMORY flag. */
281 flags
= SEC_ALLOC
| SEC_LOAD
| SEC_HAS_CONTENTS
| SEC_IN_MEMORY
;
283 /* We choose to use the name ".linux-dynamic" for the fixup table.
285 s
= bfd_make_section_with_flags (abfd
, ".linux-dynamic", flags
);
287 || ! bfd_set_section_alignment (abfd
, s
, 2))
295 /* Function to add a single symbol to the linker hash table. This is
296 a wrapper around _bfd_generic_link_add_one_symbol which handles the
297 tweaking needed for dynamic linking support. */
300 linux_add_one_symbol (struct bfd_link_info
*info
,
309 struct bfd_link_hash_entry
**hashp
)
311 struct linux_link_hash_entry
*h
;
314 /* Look up and see if we already have this symbol in the hash table.
315 If we do, and the defining entry is from a shared library, we
316 need to create the dynamic sections.
318 FIXME: What if abfd->xvec != info->output_bfd->xvec? We may
319 want to be able to link Linux a.out and ELF objects together,
320 but serious confusion is possible. */
324 if (! info
->relocatable
325 && linux_hash_table (info
)->dynobj
== NULL
326 && strcmp (name
, SHARABLE_CONFLICTS
) == 0
327 && (flags
& BSF_CONSTRUCTOR
) != 0
328 && abfd
->xvec
== info
->output_bfd
->xvec
)
330 if (! linux_link_create_dynamic_sections (abfd
, info
))
332 linux_hash_table (info
)->dynobj
= abfd
;
336 if (bfd_is_abs_section (section
)
337 && abfd
->xvec
== info
->output_bfd
->xvec
)
339 h
= linux_link_hash_lookup (linux_hash_table (info
), name
, FALSE
,
342 && (h
->root
.root
.type
== bfd_link_hash_defined
343 || h
->root
.root
.type
== bfd_link_hash_defweak
))
348 *hashp
= (struct bfd_link_hash_entry
*) h
;
350 f
= new_fixup (info
, h
, value
, ! IS_PLT_SYM (name
));
353 f
->jump
= IS_PLT_SYM (name
);
359 /* Do the usual procedure for adding a symbol. */
360 if (! _bfd_generic_link_add_one_symbol (info
, abfd
, name
, flags
, section
,
361 value
, string
, copy
, collect
,
365 /* Insert a pointer to our table in the set vector. The dynamic
366 linker requires this information. */
371 /* Here we do our special thing to add the pointer to the
372 dynamic section in the SHARABLE_CONFLICTS set vector. */
373 s
= bfd_get_section_by_name (linux_hash_table (info
)->dynobj
,
375 BFD_ASSERT (s
!= NULL
);
377 if (! (_bfd_generic_link_add_one_symbol
378 (info
, linux_hash_table (info
)->dynobj
, SHARABLE_CONFLICTS
,
379 BSF_GLOBAL
| BSF_CONSTRUCTOR
, s
, (bfd_vma
) 0, NULL
,
380 FALSE
, FALSE
, NULL
)))
387 /* We will crawl the hash table and come here for every global symbol.
388 We will examine each entry and see if there are indications that we
389 need to add a fixup. There are two possible cases - one is where
390 you have duplicate definitions of PLT or GOT symbols - these will
391 have already been caught and added as "builtin" fixups. If we find
392 that the corresponding non PLT/GOT symbol is also present, we
393 convert it to a regular fixup instead.
395 This function is called via linux_link_hash_traverse. */
398 linux_tally_symbols (struct linux_link_hash_entry
*h
, void * data
)
400 struct bfd_link_info
*info
= (struct bfd_link_info
*) data
;
401 struct fixup
*f
, *f1
;
403 struct linux_link_hash_entry
*h1
, *h2
;
406 if (h
->root
.root
.type
== bfd_link_hash_undefined
407 && CONST_STRNEQ (h
->root
.root
.root
.string
, NEEDS_SHRLIB
))
413 name
= h
->root
.root
.root
.string
+ sizeof NEEDS_SHRLIB
- 1;
414 p
= strrchr (name
, '_');
416 alloc
= (char *) bfd_malloc ((bfd_size_type
) strlen (name
) + 1);
418 if (p
== NULL
|| alloc
== NULL
)
419 (*_bfd_error_handler
) (_("Output file requires shared library `%s'\n"),
423 strcpy (alloc
, name
);
424 p
= strrchr (alloc
, '_');
426 (*_bfd_error_handler
)
427 (_("Output file requires shared library `%s.so.%s'\n"),
435 /* If this symbol is not a PLT/GOT, we do not even need to look at
437 is_plt
= IS_PLT_SYM (h
->root
.root
.root
.string
);
439 if (is_plt
|| IS_GOT_SYM (h
->root
.root
.root
.string
))
441 /* Look up this symbol twice. Once just as a regular lookup,
442 and then again following all of the indirect links until we
443 reach a real symbol. */
444 h1
= linux_link_hash_lookup (linux_hash_table (info
),
445 (h
->root
.root
.root
.string
446 + sizeof PLT_REF_PREFIX
- 1),
448 /* h2 does not follow indirect symbols. */
449 h2
= linux_link_hash_lookup (linux_hash_table (info
),
450 (h
->root
.root
.root
.string
451 + sizeof PLT_REF_PREFIX
- 1),
452 FALSE
, FALSE
, FALSE
);
454 /* The real symbol must exist but if it is also an ABS symbol,
455 there is no need to have a fixup. This is because they both
456 came from the same library. If on the other hand, we had to
457 use an indirect symbol to get to the real symbol, we add the
458 fixup anyway, since there are cases where these symbols come
459 from different shared libraries */
461 && (((h1
->root
.root
.type
== bfd_link_hash_defined
462 || h1
->root
.root
.type
== bfd_link_hash_defweak
)
463 && ! bfd_is_abs_section (h1
->root
.root
.u
.def
.section
))
464 || h2
->root
.root
.type
== bfd_link_hash_indirect
))
466 /* See if there is a "builtin" fixup already present
467 involving this symbol. If so, convert it to a regular
468 fixup. In the end, this relaxes some of the requirements
469 about the order of performing fixups. */
471 for (f1
= linux_hash_table (info
)->fixup_list
;
475 if ((f1
->h
!= h
&& f1
->h
!= h1
)
476 || (! f1
->builtin
&& ! f1
->jump
))
481 && bfd_is_abs_section (h
->root
.root
.u
.def
.section
))
483 f
= new_fixup (info
, h1
, f1
->h
->root
.root
.u
.def
.value
, 0);
492 && bfd_is_abs_section (h
->root
.root
.u
.def
.section
))
494 f
= new_fixup (info
, h1
, h
->root
.root
.u
.def
.value
, 0);
497 /* FIXME: No way to return error. */
504 /* Quick and dirty way of stripping these symbols from the
506 if (bfd_is_abs_section (h
->root
.root
.u
.def
.section
))
507 h
->root
.written
= TRUE
;
513 /* This is called to set the size of the .linux-dynamic section is.
514 It is called by the Linux linker emulation before_allocation
515 routine. We have finished reading all of the input files, and now
516 we just scan the hash tables to find out how many additional fixups
520 bfd_sparclinux_size_dynamic_sections (bfd
*output_bfd
,
521 struct bfd_link_info
*info
)
526 if (output_bfd
->xvec
!= &MY(vec
))
529 /* First find the fixups... */
530 linux_link_hash_traverse (linux_hash_table (info
),
534 /* If there are builtin fixups, leave room for a marker. This is
535 used by the dynamic linker so that it knows that all that follow
536 are builtin fixups instead of regular fixups. */
537 for (f
= linux_hash_table (info
)->fixup_list
; f
!= NULL
; f
= f
->next
)
541 ++linux_hash_table (info
)->fixup_count
;
542 ++linux_hash_table (info
)->local_builtins
;
547 if (linux_hash_table (info
)->dynobj
== NULL
)
549 if (linux_hash_table (info
)->fixup_count
> 0)
554 /* Allocate memory for our fixup table. We will fill it in later. */
555 s
= bfd_get_section_by_name (linux_hash_table (info
)->dynobj
,
559 s
->size
= linux_hash_table (info
)->fixup_count
+ 1;
561 s
->contents
= (bfd_byte
*) bfd_zalloc (output_bfd
, s
->size
);
562 if (s
->contents
== NULL
)
569 /* We come here once we are ready to actually write the fixup table to
570 the output file. Scan the fixup tables and so forth and generate
571 the stuff we need. */
574 linux_finish_dynamic_link (bfd
*output_bfd
, struct bfd_link_info
*info
)
576 asection
*s
, *os
, *is
;
577 bfd_byte
*fixup_table
;
578 struct linux_link_hash_entry
*h
;
580 unsigned int new_addr
;
582 unsigned int fixups_written
;
584 if (linux_hash_table (info
)->dynobj
== NULL
)
587 s
= bfd_get_section_by_name (linux_hash_table (info
)->dynobj
,
589 BFD_ASSERT (s
!= NULL
);
590 os
= s
->output_section
;
593 #ifdef LINUX_LINK_DEBUG
594 printf ("Fixup table file offset: %x VMA: %x\n",
595 os
->filepos
+ s
->output_offset
,
596 os
->vma
+ s
->output_offset
);
599 fixup_table
= s
->contents
;
600 bfd_put_32 (output_bfd
,
601 (bfd_vma
) linux_hash_table (info
)->fixup_count
, fixup_table
);
604 /* Fill in fixup table. */
605 for (f
= linux_hash_table (info
)->fixup_list
; f
!= NULL
; f
= f
->next
)
610 if (f
->h
->root
.root
.type
!= bfd_link_hash_defined
611 && f
->h
->root
.root
.type
!= bfd_link_hash_defweak
)
613 (*_bfd_error_handler
)
614 (_("Symbol %s not defined for fixups\n"),
615 f
->h
->root
.root
.root
.string
);
619 is
= f
->h
->root
.root
.u
.def
.section
;
620 section_offset
= is
->output_section
->vma
+ is
->output_offset
;
621 new_addr
= f
->h
->root
.root
.u
.def
.value
+ section_offset
;
623 #ifdef LINUX_LINK_DEBUG
624 printf ("Fixup(%d) %s: %x %x\n",f
->jump
, f
->h
->root
.root
.string
,
630 /* Relative address */
631 new_addr
= new_addr
- (f
->value
+ 5);
632 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
634 bfd_put_32 (output_bfd
, f
->value
+ 1, fixup_table
);
639 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
641 bfd_put_32 (output_bfd
, f
->value
, fixup_table
);
647 if (linux_hash_table (info
)->local_builtins
!= 0)
649 /* Special marker so we know to switch to the other type of fixup */
650 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
652 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
655 for (f
= linux_hash_table (info
)->fixup_list
; f
!= NULL
; f
= f
->next
)
660 if (f
->h
->root
.root
.type
!= bfd_link_hash_defined
661 && f
->h
->root
.root
.type
!= bfd_link_hash_defweak
)
663 (*_bfd_error_handler
)
664 (_("Symbol %s not defined for fixups\n"),
665 f
->h
->root
.root
.root
.string
);
669 is
= f
->h
->root
.root
.u
.def
.section
;
670 section_offset
= is
->output_section
->vma
+ is
->output_offset
;
671 new_addr
= f
->h
->root
.root
.u
.def
.value
+ section_offset
;
673 #ifdef LINUX_LINK_DEBUG
674 printf ("Fixup(B) %s: %x %x\n", f
->h
->root
.root
.string
,
678 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
680 bfd_put_32 (output_bfd
, f
->value
, fixup_table
);
686 if (linux_hash_table (info
)->fixup_count
!= fixups_written
)
688 (*_bfd_error_handler
) (_("Warning: fixup count mismatch\n"));
689 while (linux_hash_table (info
)->fixup_count
> fixups_written
)
691 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
693 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
699 h
= linux_link_hash_lookup (linux_hash_table (info
),
700 "__BUILTIN_FIXUPS__",
701 FALSE
, FALSE
, FALSE
);
704 && (h
->root
.root
.type
== bfd_link_hash_defined
705 || h
->root
.root
.type
== bfd_link_hash_defweak
))
707 is
= h
->root
.root
.u
.def
.section
;
708 section_offset
= is
->output_section
->vma
+ is
->output_offset
;
709 new_addr
= h
->root
.root
.u
.def
.value
+ section_offset
;
711 #ifdef LINUX_LINK_DEBUG
712 printf ("Builtin fixup table at %x\n", new_addr
);
715 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
718 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
720 if (bfd_seek (output_bfd
, (file_ptr
) (os
->filepos
+ s
->output_offset
),
724 if (bfd_bwrite (s
->contents
, s
->size
, output_bfd
) != s
->size
)
730 #define MY_bfd_link_hash_table_create linux_link_hash_table_create
731 #define MY_add_one_symbol linux_add_one_symbol
732 #define MY_finish_dynamic_link linux_finish_dynamic_link
734 #define MY_zmagic_contiguous 1
736 #include "aout-target.h"