1 /* Machine-dependent ELF dynamic relocation inline functions. CRIS version.
2 Copyright (C) 1996-2001, 2002 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 #define ELF_MACHINE_NAME "CRIS"
25 #include <sys/param.h>
29 "move.d $pc,$r9\n\t" \
30 "add.d " #x " - .,$r9\n\t" \
33 # define CALL_FN(x) "jsr " #x
36 /* Return nonzero iff ELF header is compatible with the running host. */
39 elf_machine_matches_host (const Elf32_Ehdr
*ehdr
)
41 return ehdr
->e_machine
== EM_CRIS
;
44 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
45 first element of the GOT. This must be inlined in a function which
48 static inline Elf32_Addr
49 elf_machine_dynamic (void)
51 /* Don't just set this to an asm variable "r0" since that's not logical
52 (like, the variable is uninitialized and the register is fixed) and
53 may make GCC trip over itself doing register allocation. Yes, I'm
54 paranoid. Why do you ask? */
57 __asm__ ("move.d $r0,%0" : "=rm" (got
));
61 /* Return the run-time load address of the shared object. We do it like
62 m68k and i386, by taking an arbitrary local symbol, forcing a GOT entry
63 for it, and peeking into the GOT table, which is set to the link-time
64 file-relative symbol value (regardless of whether the target is REL or
65 RELA). We subtract this link-time file-relative value from the "local"
66 value we calculate from GOT position and GOT offset. FIXME: Perhaps
67 there's some other symbol we could use, that we don't *have* to force a
70 static inline Elf32_Addr
71 elf_machine_load_address (void)
73 Elf32_Addr gotaddr_diff
;
74 __asm__ ("sub.d [$r0+_dl_start:GOT16],$r0,%0\n\t"
75 "add.d _dl_start:GOTOFF,%0" : "=r" (gotaddr_diff
));
79 /* Set up the loaded object described by L so its unrelocated PLT
80 entries will jump to the on-demand fixup code in dl-runtime.c. */
83 elf_machine_runtime_setup (struct link_map
*l
, int lazy
, int profile
)
86 extern void _dl_runtime_resolve (Elf32_Word
);
87 extern void _dl_runtime_profile (Elf32_Word
);
89 if (l
->l_info
[DT_JMPREL
] && lazy
)
91 /* The GOT entries for functions in the PLT have not yet been
92 filled in. Their initial contents will arrange when called
93 to push an offset into the .rela.plt section, push
94 _GLOBAL_OFFSET_TABLE_[1], and then jump to
95 _GLOBAL_OFFSET_TABLE_[2]. */
96 got
= (Elf32_Addr
*) D_PTR (l
, l_info
[DT_PLTGOT
]);
97 got
[1] = (Elf32_Addr
) l
; /* Identify this shared object. */
99 /* The got[2] entry contains the address of a function which gets
100 called to get the address of a so far unresolved function and
101 jump to it. The profiling extension of the dynamic linker allows
102 to intercept the calls to collect information. In this case we
103 don't store the address in the GOT so that all future calls also
104 end in this function. */
105 if (__builtin_expect (profile
, 0))
107 got
[2] = (Elf32_Addr
) &_dl_runtime_profile
;
109 if (_dl_name_match_p (GL(dl_profile
), l
))
111 /* This is the object we are looking for. Say that we really
112 want profiling and the timers are started. */
113 GL(dl_profile_map
) = l
;
117 /* This function will get called to fix up the GOT entry indicated by
118 the offset on the stack, and then jump to the resolved address. */
119 got
[2] = (Elf32_Addr
) &_dl_runtime_resolve
;
125 /* This code is used in dl-runtime.c to call the `fixup' function
126 and then redirect to the address it returns.
128 We get here with the offset into the relocation table pushed on stack,
129 and the link map in MOF. */
131 #define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name) \
132 "; Trampoline for " #fixup_name "
133 .globl " #tramp_name "
134 .type " #tramp_name ", @function
142 move.d [$sp+6*4],$r11
144 " CALL_FN (fixup_name) "
145 move.d $r10,[$sp+6*4]
153 .size " #tramp_name ", . - " #tramp_name "\n"
155 #define ELF_MACHINE_RUNTIME_TRAMPOLINE \
156 asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \
157 TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup));
159 #define ELF_MACHINE_RUNTIME_TRAMPOLINE \
160 asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \
161 ".globl _dl_runtime_profile\n" \
162 ".set _dl_runtime_profile, _dl_runtime_resolve");
166 /* Mask identifying addresses reserved for the user program,
167 where the dynamic linker should not map anything. */
168 #define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL
170 /* Initial entry point code for the dynamic linker.
171 The C function `_dl_start' is the real entry point;
172 its return value is the user program's entry point. */
174 #define RTLD_START asm ("\
177 .type _start,@function
180 " CALL_FN (_dl_start) "
183 .globl _dl_start_user
184 .type _dl_start_user,@function
186 ; Save the user entry point address in R1.
188 ; Point R0 at the GOT.
191 ; Remember the highest stack address.
192 move.d [$r0+__libc_stack_end:GOT16],$r13
194 ; See if we were run as a command with the executable file
195 ; name as an extra leading argument.
196 move.d [$r0+_dl_skip_args:GOT16],$r13
198 ; Get the original argument count
200 ; Subtract _dl_skip_args from it.
202 ; Adjust the stack pointer to skip _dl_skip_args words.
204 ; Put the new argc in place as expected by the user entry.
206 ; Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)
207 ; env: skip scaled argc and skip stored argc and NULL at end of argv[].
211 ; argv: skip stored argc.
214 ; main_map: at _dl_loaded.
215 move.d [$r0+_rtld_global:GOT16],$r9
217 move.d _dl_init_internal:PLTG,$r9
220 ; Pass our finalizer function to the user in R10.
221 move.d [$r0+_dl_fini:GOT16],$r10
222 ; Terminate the frame-pointer.
224 ; Cause SEGV if user entry returns.
226 ; Jump to the user's entry point.
228 .size _dl_start_user, . - _dl_start_user
231 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
232 PLT entries should not be allowed to define the value.
233 ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
234 of the main executable's symbols, as for a COPY reloc. */
235 #define elf_machine_type_class(type) \
236 ((((type) == R_CRIS_JUMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
237 | (((type) == R_CRIS_COPY) * ELF_RTYPE_CLASS_COPY))
239 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
240 #define ELF_MACHINE_JMP_SLOT R_CRIS_JUMP_SLOT
242 /* CRIS never uses Elf32_Rel relocations. */
243 #define ELF_MACHINE_NO_REL 1
245 /* We define an initialization functions. This is called very early in
247 #define DL_PLATFORM_INIT dl_platform_init ()
249 static inline void __attribute__ ((unused
))
250 dl_platform_init (void)
252 if (GL(dl_platform
) != NULL
&& *GL(dl_platform
) == '\0')
253 /* Avoid an empty string which would disturb us. */
254 GL(dl_platform
) = NULL
;
257 static inline Elf32_Addr
258 elf_machine_fixup_plt (struct link_map
*map
, lookup_t t
,
259 const Elf32_Rela
*reloc
,
260 Elf32_Addr
*reloc_addr
, Elf32_Addr value
)
262 return *reloc_addr
= value
;
265 /* Return the final value of a plt relocation. */
266 static inline Elf32_Addr
267 elf_machine_plt_value (struct link_map
*map
, const Elf32_Rela
*reloc
,
270 return value
+ reloc
->r_addend
;
273 #endif /* !dl_machine_h */
277 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
278 MAP is the object containing the reloc. */
281 elf_machine_rela (struct link_map
*map
, const Elf32_Rela
*reloc
,
282 const Elf32_Sym
*sym
, const struct r_found_version
*version
,
283 Elf32_Addr
*const reloc_addr
)
285 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
287 if (__builtin_expect (r_type
== R_CRIS_RELATIVE
, 0))
288 *reloc_addr
= map
->l_addr
+ reloc
->r_addend
;
291 #ifndef RTLD_BOOTSTRAP
292 const Elf32_Sym
*const refsym
= sym
;
295 if (sym
->st_shndx
!= SHN_UNDEF
296 && ELF32_ST_BIND (sym
->st_info
) == STB_LOCAL
)
300 value
= RESOLVE (&sym
, version
, r_type
);
302 value
+= sym
->st_value
;
304 value
+= reloc
->r_addend
; /* Assume copy relocs have zero addend. */
308 #ifndef RTLD_BOOTSTRAP
311 /* This can happen in trace mode if an object could not be
314 if (sym
->st_size
> refsym
->st_size
315 || (GL(dl_verbose
) && sym
->st_size
< refsym
->st_size
))
317 extern char **_dl_argv
;
320 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
322 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
323 _dl_argv
[0] ?: "<program name unknown>",
324 strtab
+ refsym
->st_name
);
326 memcpy (reloc_addr
, (void *) value
, MIN (sym
->st_size
,
332 case R_CRIS_GLOB_DAT
:
333 case R_CRIS_JUMP_SLOT
:
336 #ifndef RTLD_BOOTSTRAP
338 *(char *) reloc_addr
= value
;
341 *(short *) reloc_addr
= value
;
345 = value
+ reloc
->r_addend
- (Elf32_Addr
) reloc_addr
- 1;
347 case R_CRIS_16_PCREL
:
348 *(short *) reloc_addr
349 = value
+ reloc
->r_addend
- (Elf32_Addr
) reloc_addr
- 2;
351 case R_CRIS_32_PCREL
:
352 *reloc_addr
= value
+ reloc
->r_addend
- (Elf32_Addr
) reloc_addr
- 4;
357 #if !defined RTLD_BOOTSTRAP || defined _NDEBUG
359 _dl_reloc_bad_type (map
, r_type
, 0);
367 elf_machine_rela_relative (Elf32_Addr l_addr
, const Elf32_Rela
*reloc
,
368 Elf32_Addr
*const reloc_addr
)
370 *reloc_addr
= l_addr
+ reloc
->r_addend
;
374 elf_machine_lazy_rel (struct link_map
*map
,
375 Elf32_Addr l_addr
, const Elf32_Rela
*reloc
)
377 Elf32_Addr
*const reloc_addr
= (void *) (l_addr
+ reloc
->r_offset
);
378 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
379 if (__builtin_expect (r_type
== R_CRIS_JUMP_SLOT
, 1))
380 *reloc_addr
+= l_addr
;
382 _dl_reloc_bad_type (map
, r_type
, 1);