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1 /* Machine-dependent ELF dynamic relocation inline functions. S390 Version.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
3 Contributed by Carl Pederson & Martin Schwidefsky.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library 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 GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
25 #define ELF_MACHINE_NAME "s390"
27 #include <sys/param.h>
31 /* This is an older, now obsolete value. */
32 #define EM_S390_OLD 0xA390
34 /* Return nonzero iff ELF header is compatible with the running host. */
36 elf_machine_matches_host (const Elf32_Ehdr
*ehdr
)
38 return (ehdr
->e_machine
== EM_S390
|| ehdr
->e_machine
== EM_S390_OLD
)
39 && ehdr
->e_ident
[EI_CLASS
] == ELFCLASS32
;
43 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
44 first element of the GOT. This must be inlined in a function which
47 static inline Elf32_Addr
48 elf_machine_dynamic (void)
50 register Elf32_Addr
*got
;
53 "1: .long _GLOBAL_OFFSET_TABLE_-1b\n"
55 : "=&a" (got
) : : "0" );
61 /* Return the run-time load address of the shared object. */
62 static inline Elf32_Addr
63 elf_machine_load_address (void)
68 "1: .long _GLOBAL_OFFSET_TABLE_ - 1b\n"
69 " .long _dl_start - 1b - 0x80000000\n"
73 " sl %0,_dl_start@GOT12(1)"
74 : "=&d" (addr
) : : "1" );
78 /* Set up the loaded object described by L so its unrelocated PLT
79 entries will jump to the on-demand fixup code in dl-runtime.c. */
81 static inline int __attribute__ ((unused
))
82 elf_machine_runtime_setup (struct link_map
*l
, int lazy
, int profile
)
84 extern void _dl_runtime_resolve (Elf32_Word
);
85 extern void _dl_runtime_profile (Elf32_Word
);
87 if (l
->l_info
[DT_JMPREL
] && lazy
)
89 /* The GOT entries for functions in the PLT have not yet been filled
90 in. Their initial contents will arrange when called to push an
91 offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
92 and then jump to _GLOBAL_OFFSET_TABLE[2]. */
94 got
= (Elf32_Addr
*) D_PTR (l
, l_info
[DT_PLTGOT
]);
95 /* If a library is prelinked but we have to relocate anyway,
96 we have to be able to undo the prelinking of .got.plt.
97 The prelinker saved us here address of .plt + 0x2c. */
100 l
->l_mach
.plt
= got
[1] + l
->l_addr
;
101 l
->l_mach
.gotplt
= (Elf32_Addr
) &got
[3];
103 got
[1] = (Elf32_Addr
) l
; /* Identify this shared object. */
105 /* The got[2] entry contains the address of a function which gets
106 called to get the address of a so far unresolved function and
107 jump to it. The profiling extension of the dynamic linker allows
108 to intercept the calls to collect information. In this case we
109 don't store the address in the GOT so that all future calls also
110 end in this function. */
111 if (__builtin_expect (profile
, 0))
113 got
[2] = (Elf32_Addr
) &_dl_runtime_profile
;
115 if (_dl_name_match_p (GLRO(dl_profile
), l
))
116 /* This is the object we are looking for. Say that we really
117 want profiling and the timers are started. */
118 GL(dl_profile_map
) = l
;
121 /* This function will get called to fix up the GOT entry indicated by
122 the offset on the stack, and then jump to the resolved address. */
123 got
[2] = (Elf32_Addr
) &_dl_runtime_resolve
;
129 /* This code is used in dl-runtime.c to call the `fixup' function
130 and then redirect to the address it returns. */
133 Arguments are in register.
134 r2 - r7 holds the original parameters for the function call, fixup
135 and trampoline code use r0-r5 and r14-15. For the correct function
136 call r2-r5 and r14-15 must be restored.
137 Arguments from the PLT are stored at 24(r15) and 28(r15)
138 and must be moved to r2 and r3 for the fixup call (see elf32-s390.c
139 in the binutils for the PLT code).
140 Fixup function address in r2.
143 #define ELF_MACHINE_RUNTIME_TRAMPOLINE \
146 .globl _dl_runtime_resolve\n\
147 .type _dl_runtime_resolve, @function\n\
150 _dl_runtime_resolve:\n\
156 " CFI_ADJUST_CFA_OFFSET(96)"\n\
158 # load args saved by PLT\n\
163 bas 14,0(14,1) # call fixup\n\
164 lr 1,2 # function addr returned in r2\n\
165 # restore registers\n\
167 " CFI_ADJUST_CFA_OFFSET(-96)" \n\
173 .size _dl_runtime_resolve, .-_dl_runtime_resolve\n\
175 .globl _dl_runtime_profile\n\
176 .type _dl_runtime_profile, @function\n\
179 _dl_runtime_profile:\n\
185 " CFI_ADJUST_CFA_OFFSET(96)"\n\
187 # load args saved by PLT\n\
189 # load return address as third parameter\n\
194 bas 14,0(14,1) # call fixup\n\
195 lr 1,2 # function addr returned in r2\n\
196 # restore registers\n\
198 " CFI_ADJUST_CFA_OFFSET(-96)" \n\
202 1: .long profile_fixup-1b\n\
204 .size _dl_runtime_profile, .-_dl_runtime_profile\n\
207 #define ELF_MACHINE_RUNTIME_TRAMPOLINE \
210 .globl _dl_runtime_resolve\n\
211 .globl _dl_runtime_profile\n\
212 .type _dl_runtime_resolve, @function\n\
213 .type _dl_runtime_profile, @function\n\
216 _dl_runtime_resolve:\n\
217 _dl_runtime_profile:\n\
223 " CFI_ADJUST_CFA_OFFSET(96)"\n\
225 # load args saved by PLT\n\
227 # load return address as third parameter\n\
232 bas 14,0(14,1) # call fixup\n\
233 lr 1,2 # function addr returned in r2\n\
234 # restore registers\n\
236 " CFI_ADJUST_CFA_OFFSET(-96)" \n\
242 .size _dl_runtime_resolve, .-_dl_runtime_resolve\n\
243 .size _dl_runtime_profile, .-_dl_runtime_profile\n\
247 /* Mask identifying addresses reserved for the user program,
248 where the dynamic linker should not map anything. */
249 #define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL
251 /* Initial entry point code for the dynamic linker.
252 The C function `_dl_start' is the real entry point;
253 its return value is the user program's entry point. */
255 #define RTLD_START asm ("\n\
259 .globl _dl_start_user\n\
262 .L0: ahi %r13,.Llit-.L0\n\
264 # Alloc stack frame\n\
266 # Set the back chain to zero\n\
267 xc 0(4,%r15),0(%r15)\n\
268 # Call _dl_start with %r2 pointing to arg on stack\n\
269 l %r14,.Ladr1-.Llit(%r13)\n\
270 bas %r14,0(%r14,%r13) # call _dl_start\n\
272 # Save the user entry point address in %r8.\n\
274 # Point %r12 at the GOT.\n\
275 l %r12,.Ladr0-.Llit(%r13)\n\
277 # See if we were run as a command with the executable file\n\
278 # name as an extra leading argument.\n\
279 l %r1,_dl_skip_args@GOT12(0,%r12)\n\
280 l %r1,0(%r1) # load _dl_skip_args\n\
281 # Get the original argument count.\n\
283 # Subtract _dl_skip_args from it.\n\
285 # Adjust the stack pointer to skip _dl_skip_args words.\n\
288 # Set the back chain to zero again\n\
289 xc 0(4,%r15),0(%r15)\n\
290 # Store back the modified argument count.\n\
292 # The special initializer gets called with the stack just\n\
293 # as the application's entry point will see it; it can\n\
294 # switch stacks if it moves these contents over.\n\
295 " RTLD_START_SPECIAL_INIT "\n\
296 # Call the function to run the initializers.\n\
297 # Load the parameters:\n\
298 # (%r2, %r3, %r4, %r5) = (_dl_loaded, argc, argv, envp)\n\
299 l %r2,_rtld_local@GOT(%r12)\n\
305 la %r5,104(%r5,%r15)\n\
306 l %r1,.Ladr4-.Llit(%r13)\n\
307 bas %r14,0(%r1,%r13)\n\
308 # Pass our finalizer function to the user in %r14, as per ELF ABI.\n\
309 l %r14,_dl_fini@GOT(%r12)\n\
310 # Free stack frame\n\
312 # Jump to the user's entry point (saved in %r8).\n\
315 .Ladr0: .long _GLOBAL_OFFSET_TABLE_-.Llit\n\
316 .Ladr1: .long _dl_start-.Llit\n\
317 .Ladr4: .long _dl_init_internal@PLT-.Llit\n\
320 #ifndef RTLD_START_SPECIAL_INIT
321 #define RTLD_START_SPECIAL_INIT /* nothing */
324 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
325 TLS variable, so undefined references should not be allowed to
327 ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
328 of the main executable's symbols, as for a COPY reloc. */
330 # define elf_machine_type_class(type) \
331 ((((type) == R_390_JMP_SLOT || (type) == R_390_TLS_DTPMOD \
332 || (type) == R_390_TLS_DTPOFF || (type) == R_390_TLS_TPOFF) \
333 * ELF_RTYPE_CLASS_PLT) \
334 | (((type) == R_390_COPY) * ELF_RTYPE_CLASS_COPY))
336 # define elf_machine_type_class(type) \
337 ((((type) == R_390_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
338 | (((type) == R_390_COPY) * ELF_RTYPE_CLASS_COPY))
341 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
342 #define ELF_MACHINE_JMP_SLOT R_390_JMP_SLOT
344 /* The S390 never uses Elf32_Rel relocations. */
345 #define ELF_MACHINE_NO_REL 1
347 /* The S390 overlaps DT_RELA and DT_PLTREL. */
348 #define ELF_MACHINE_PLTREL_OVERLAP 1
350 /* We define an initialization functions. This is called very early in
352 #define DL_PLATFORM_INIT dl_platform_init ()
354 static inline void __attribute__ ((unused
))
355 dl_platform_init (void)
357 if (GLRO(dl_platform
) != NULL
&& *GLRO(dl_platform
) == '\0')
358 /* Avoid an empty string which would disturb us. */
359 GLRO(dl_platform
) = NULL
;
362 static inline Elf32_Addr
363 elf_machine_fixup_plt (struct link_map
*map
, lookup_t t
,
364 const Elf32_Rela
*reloc
,
365 Elf32_Addr
*reloc_addr
, Elf32_Addr value
)
367 return *reloc_addr
= value
;
370 /* Return the final value of a plt relocation. */
371 static inline Elf32_Addr
372 elf_machine_plt_value (struct link_map
*map
, const Elf32_Rela
*reloc
,
378 #endif /* !dl_machine_h */
383 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
384 MAP is the object containing the reloc. */
387 elf_machine_rela (struct link_map
*map
, const Elf32_Rela
*reloc
,
388 const Elf32_Sym
*sym
, const struct r_found_version
*version
,
389 void *const reloc_addr_arg
)
391 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
392 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
394 #if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
395 if (__builtin_expect (r_type
== R_390_RELATIVE
, 0))
397 # if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
398 /* This is defined in rtld.c, but nowhere in the static libc.a;
399 make the reference weak so static programs can still link.
400 This declaration cannot be done when compiling rtld.c
401 (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the
402 common defn for _dl_rtld_map, which is incompatible with a
403 weak decl in the same file. */
405 weak_extern (GL(dl_rtld_map
));
407 if (map
!= &GL(dl_rtld_map
)) /* Already done in rtld itself. */
409 *reloc_addr
= map
->l_addr
+ reloc
->r_addend
;
413 if (__builtin_expect (r_type
== R_390_NONE
, 0))
417 #ifndef RESOLVE_CONFLICT_FIND_MAP
418 const Elf32_Sym
*const refsym
= sym
;
420 #if defined USE_TLS && !defined RTLD_BOOTSTRAP
421 struct link_map
*sym_map
= RESOLVE_MAP (&sym
, version
, r_type
);
422 Elf32_Addr value
= sym
== NULL
? 0 : sym_map
->l_addr
+ sym
->st_value
;
424 Elf32_Addr value
= RESOLVE (&sym
, version
, r_type
);
426 # ifndef RTLD_BOOTSTRAP
429 value
+= sym
->st_value
;
430 #endif /* use TLS and !RTLD_BOOTSTRAP */
436 *reloc_addr
= value
+ reloc
->r_addend
;
439 #if defined USE_TLS && (!defined RTLD_BOOTSTRAP || USE___THREAD) \
440 && !defined RESOLVE_CONFLICT_FIND_MAP
441 case R_390_TLS_DTPMOD
:
442 # ifdef RTLD_BOOTSTRAP
443 /* During startup the dynamic linker is always the module
445 XXX If this relocation is necessary move before RESOLVE
449 /* Get the information from the link map returned by the
452 *reloc_addr
= sym_map
->l_tls_modid
;
455 case R_390_TLS_DTPOFF
:
456 # ifndef RTLD_BOOTSTRAP
457 /* During relocation all TLS symbols are defined and used.
458 Therefore the offset is already correct. */
460 *reloc_addr
= sym
->st_value
+ reloc
->r_addend
;
463 case R_390_TLS_TPOFF
:
464 /* The offset is negative, forward from the thread pointer. */
465 # ifdef RTLD_BOOTSTRAP
466 *reloc_addr
= sym
->st_value
+ reloc
->r_addend
- map
->l_tls_offset
;
468 /* We know the offset of the object the symbol is contained in.
469 It is a negative value which will be added to the
473 CHECK_STATIC_TLS (map
, sym_map
);
474 *reloc_addr
= (sym
->st_value
+ reloc
->r_addend
475 - sym_map
->l_tls_offset
);
481 #ifndef RTLD_BOOTSTRAP
482 # ifndef RESOLVE_CONFLICT_FIND_MAP
483 /* Not needed in dl-conflict.c. */
486 /* This can happen in trace mode if an object could not be
489 if (__builtin_expect (sym
->st_size
> refsym
->st_size
, 0)
490 || (__builtin_expect (sym
->st_size
< refsym
->st_size
, 0)
491 && __builtin_expect (GLRO(dl_verbose
), 0)))
495 strtab
= (const char *) D_PTR(map
,l_info
[DT_STRTAB
]);
497 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
498 rtld_progname
?: "<program name unknown>",
499 strtab
+ refsym
->st_name
);
501 memcpy (reloc_addr_arg
, (void *) value
,
502 MIN (sym
->st_size
, refsym
->st_size
));
506 *reloc_addr
= value
+ reloc
->r_addend
;
509 *(unsigned short *) reloc_addr
= value
+ reloc
->r_addend
;
512 *(char *) reloc_addr
= value
+ reloc
->r_addend
;
514 # ifndef RESOLVE_CONFLICT_FIND_MAP
516 *reloc_addr
= value
+ reloc
->r_addend
- (Elf32_Addr
) reloc_addr
;
520 *(unsigned short *) reloc_addr
= (unsigned short)
521 ((short) (value
+ reloc
->r_addend
- (Elf32_Addr
) reloc_addr
) >> 1);
524 *(unsigned short *) reloc_addr
=
525 value
+ reloc
->r_addend
- (Elf32_Addr
) reloc_addr
;
531 #if !defined(RTLD_BOOTSTRAP) || defined(_NDEBUG)
533 /* We add these checks in the version to relocate ld.so only
534 if we are still debugging. */
535 _dl_reloc_bad_type (map
, r_type
, 0);
543 elf_machine_rela_relative (Elf32_Addr l_addr
, const Elf32_Rela
*reloc
,
544 void *const reloc_addr_arg
)
546 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
547 *reloc_addr
= l_addr
+ reloc
->r_addend
;
551 elf_machine_lazy_rel (struct link_map
*map
,
552 Elf32_Addr l_addr
, const Elf32_Rela
*reloc
)
554 Elf32_Addr
*const reloc_addr
= (void *) (l_addr
+ reloc
->r_offset
);
555 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
556 /* Check for unexpected PLT reloc type. */
557 if (__builtin_expect (r_type
== R_390_JMP_SLOT
, 1))
559 if (__builtin_expect (map
->l_mach
.plt
, 0) == 0)
560 *reloc_addr
+= l_addr
;
564 + (((Elf32_Addr
) reloc_addr
) - map
->l_mach
.gotplt
) * 8;
567 _dl_reloc_bad_type (map
, r_type
, 1);