One more sanity check in free.
[glibc.git] / sysdeps / sh / dl-machine.h
blob78f70e38805d75d0f1808772756532c69e93a80c
1 /* Machine-dependent ELF dynamic relocation inline functions. SH version.
2 Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
3 Free Software Foundation, Inc.
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
19 02111-1307 USA. */
21 #ifndef dl_machine_h
22 #define dl_machine_h
24 #define ELF_MACHINE_NAME "SH"
26 #include <sys/param.h>
27 #include <sysdep.h>
28 #include <assert.h>
30 /* Return nonzero iff ELF header is compatible with the running host. */
31 static inline int __attribute__ ((unused))
32 elf_machine_matches_host (const Elf32_Ehdr *ehdr)
34 return ehdr->e_machine == EM_SH;
38 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
39 first element of the GOT. This must be inlined in a function which
40 uses global data. */
41 static inline Elf32_Addr __attribute__ ((unused))
42 elf_machine_dynamic (void)
44 register Elf32_Addr *got;
45 asm ("mov r12,%0" :"=r" (got));
46 return *got;
50 /* Return the run-time load address of the shared object. */
51 static inline Elf32_Addr __attribute__ ((unused))
52 elf_machine_load_address (void)
54 Elf32_Addr addr;
55 asm ("mov.l 1f,r0\n\
56 mov.l 3f,r2\n\
57 add r12,r2\n\
58 mov.l @(r0,r12),r0\n\
59 bra 2f\n\
60 sub r0,r2\n\
61 .align 2\n\
62 1: .long _dl_start@GOT\n\
63 3: .long _dl_start@GOTOFF\n\
64 2: mov r2,%0"
65 : "=r" (addr) : : "r0", "r1", "r2");
66 return addr;
70 /* Set up the loaded object described by L so its unrelocated PLT
71 entries will jump to the on-demand fixup code in dl-runtime.c. */
73 static inline int __attribute__ ((unused, always_inline))
74 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
76 Elf32_Addr *got;
77 extern void _dl_runtime_resolve (Elf32_Word);
78 extern void _dl_runtime_profile (Elf32_Word);
80 if (l->l_info[DT_JMPREL] && lazy)
82 /* The GOT entries for functions in the PLT have not yet been filled
83 in. Their initial contents will arrange when called to load an
84 offset into the .rela.plt section and _GLOBAL_OFFSET_TABLE_[1],
85 and then jump to _GLOBAL_OFFSET_TABLE[2]. */
86 got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
87 /* If a library is prelinked but we have to relocate anyway,
88 we have to be able to undo the prelinking of .got.plt.
89 The prelinker saved us here address of .plt + 36. */
90 if (got[1])
92 l->l_mach.plt = got[1] + l->l_addr;
93 l->l_mach.gotplt = (Elf32_Addr) &got[3];
95 got[1] = (Elf32_Addr) l; /* Identify this shared object. */
97 /* The got[2] entry contains the address of a function which gets
98 called to get the address of a so far unresolved function and
99 jump to it. The profiling extension of the dynamic linker allows
100 to intercept the calls to collect information. In this case we
101 don't store the address in the GOT so that all future calls also
102 end in this function. */
103 if (profile)
105 got[2] = (Elf32_Addr) &_dl_runtime_profile;
106 /* Say that we really want profiling and the timers are started. */
107 if (GLRO(dl_profile) != NULL
108 && _dl_name_match_p (GLRO(dl_profile), l))
109 GL(dl_profile_map) = l;
111 else
112 /* This function will get called to fix up the GOT entry indicated by
113 the offset on the stack, and then jump to the resolved address. */
114 got[2] = (Elf32_Addr) &_dl_runtime_resolve;
116 return lazy;
119 #define ELF_MACHINE_RUNTIME_FIXUP_ARGS int plt_type
121 /* Mask identifying addresses reserved for the user program,
122 where the dynamic linker should not map anything. */
123 #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
125 /* Initial entry point code for the dynamic linker.
126 The C function `_dl_start' is the real entry point;
127 its return value is the user program's entry point. */
129 #define RTLD_START asm ("\
130 .text\n\
131 .globl _start\n\
132 .globl _dl_start_user\n\
133 _start:\n\
134 mov r15,r4\n\
135 mov.l .L_dl_start,r1\n\
136 mova .L_dl_start,r0\n\
137 add r1,r0\n\
138 jsr @r0\n\
139 nop\n\
140 _dl_start_user:\n\
141 ! Save the user entry point address in r8.\n\
142 mov r0,r8\n\
143 ! Point r12 at the GOT.\n\
144 mov.l 1f,r12\n\
145 mova 1f,r0\n\
146 bra 2f\n\
147 add r0,r12\n\
148 .align 2\n\
149 1: .long _GLOBAL_OFFSET_TABLE_\n\
150 2: ! See if we were run as a command with the executable file\n\
151 ! name as an extra leading argument.\n\
152 mov.l .L_dl_skip_args,r0\n\
153 mov.l @(r0,r12),r0\n\
154 mov.l @r0,r0\n\
155 ! Get the original argument count.\n\
156 mov.l @r15,r5\n\
157 ! Subtract _dl_skip_args from it.\n\
158 sub r0,r5\n\
159 ! Adjust the stack pointer to skip _dl_skip_args words.\n\
160 shll2 r0\n\
161 add r0,r15\n\
162 ! Store back the modified argument count.\n\
163 mov.l r5,@r15\n\
164 ! Compute argv address and envp.\n\
165 mov r15,r6\n\
166 add #4,r6\n\
167 mov r5,r7\n\
168 shll2 r7\n\
169 add r15,r7\n\
170 add #8,r7\n\
171 mov.l .L_dl_loaded,r0\n\
172 mov.l @(r0,r12),r0\n\
173 mov.l @r0,r4\n\
174 ! Call _dl_init.\n\
175 mov.l .L_dl_init,r1\n\
176 mova .L_dl_init,r0\n\
177 add r1,r0\n\
178 jsr @r0\n\
179 nop\n\
180 1: ! Pass our finalizer function to the user in r4, as per ELF ABI.\n\
181 mov.l .L_dl_fini,r0\n\
182 mov.l @(r0,r12),r4\n\
183 ! Jump to the user's entry point.\n\
184 jmp @r8\n\
185 nop\n\
186 .align 2\n\
187 .L_dl_start:\n\
188 .long _dl_start@PLT\n\
189 .L_dl_skip_args:\n\
190 .long _dl_skip_args@GOT\n\
191 .L_dl_init:\n\
192 .long _dl_init_internal@PLT\n\
193 .L_dl_loaded:\n\
194 .long _rtld_local@GOT\n\
195 .L_dl_fini:\n\
196 .long _dl_fini@GOT\n\
197 .type __fpscr_values,@object\n\
198 .global __fpscr_values\n\
199 __fpscr_values:\n\
200 .long 0\n\
201 .long 0x80000\n\
202 .weak __fpscr_values\n\
203 .previous\n\
206 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
207 TLS variable, so undefined references should not be allowed to
208 define the value.
209 ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
210 of the main executable's symbols, as for a COPY reloc. */
211 #if !defined RTLD_BOOTSTRAP || USE___THREAD
212 # define elf_machine_type_class(type) \
213 ((((type) == R_SH_JMP_SLOT || (type) == R_SH_TLS_DTPMOD32 \
214 || (type) == R_SH_TLS_DTPOFF32 || (type) == R_SH_TLS_TPOFF32) \
215 * ELF_RTYPE_CLASS_PLT) \
216 | (((type) == R_SH_COPY) * ELF_RTYPE_CLASS_COPY))
217 #else
218 #define elf_machine_type_class(type) \
219 ((((type) == R_SH_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
220 | (((type) == R_SH_COPY) * ELF_RTYPE_CLASS_COPY))
221 #endif
223 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
224 #define ELF_MACHINE_JMP_SLOT R_SH_JMP_SLOT
226 /* We define an initialization functions. This is called very early in
227 _dl_sysdep_start. */
228 #define DL_PLATFORM_INIT dl_platform_init ()
230 static inline void __attribute__ ((unused))
231 dl_platform_init (void)
233 if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
234 /* Avoid an empty string which would disturb us. */
235 GLRO(dl_platform) = NULL;
238 static inline Elf32_Addr
239 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
240 const Elf32_Rela *reloc,
241 Elf32_Addr *reloc_addr, Elf32_Addr value)
243 return *reloc_addr = value;
246 /* Return the final value of a plt relocation. */
247 static inline Elf32_Addr
248 elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
249 Elf32_Addr value)
251 return value + reloc->r_addend;
254 #define ARCH_LA_PLTENTER sh_gnu_pltenter
255 #define ARCH_LA_PLTEXIT sh_gnu_pltexit
257 #endif /* !dl_machine_h */
259 /* SH never uses Elf32_Rel relocations. */
260 #define ELF_MACHINE_NO_REL 1
262 #ifdef RESOLVE_MAP
264 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
265 MAP is the object containing the reloc. */
267 auto inline void
268 __attribute ((always_inline))
269 elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
270 const Elf32_Sym *sym, const struct r_found_version *version,
271 void *const reloc_addr_arg)
273 Elf32_Addr *const reloc_addr = reloc_addr_arg;
274 const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
275 Elf32_Addr value;
277 #define COPY_UNALIGNED_WORD(swp, twp, align) \
279 void *__s = (swp), *__t = (twp); \
280 unsigned char *__s1 = __s, *__t1 = __t; \
281 unsigned short *__s2 = __s, *__t2 = __t; \
282 unsigned long *__s4 = __s, *__t4 = __t; \
283 switch ((align)) \
285 case 0: \
286 *__t4 = *__s4; \
287 break; \
288 case 2: \
289 *__t2++ = *__s2++; \
290 *__t2 = *__s2; \
291 break; \
292 default: \
293 *__t1++ = *__s1++; \
294 *__t1++ = *__s1++; \
295 *__t1++ = *__s1++; \
296 *__t1 = *__s1; \
297 break; \
301 if (__builtin_expect (r_type == R_SH_RELATIVE, 0))
303 #ifndef RTLD_BOOTSTRAP
304 if (map != &GL(dl_rtld_map)) /* Already done in rtld itself. */
305 #endif
307 if (reloc->r_addend)
308 value = map->l_addr + reloc->r_addend;
309 else
311 COPY_UNALIGNED_WORD (reloc_addr_arg, &value,
312 (int) reloc_addr_arg & 3);
313 value += map->l_addr;
315 COPY_UNALIGNED_WORD (&value, reloc_addr_arg,
316 (int) reloc_addr_arg & 3);
319 #ifndef RTLD_BOOTSTRAP
320 else if (__builtin_expect (r_type == R_SH_NONE, 0))
321 return;
322 #endif
323 else
325 const Elf32_Sym *const refsym = sym;
326 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
328 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
329 value += reloc->r_addend;
331 switch (r_type)
333 case R_SH_COPY:
334 if (sym == NULL)
335 /* This can happen in trace mode if an object could not be
336 found. */
337 break;
338 if (sym->st_size > refsym->st_size
339 || (sym->st_size < refsym->st_size && GLRO(dl_verbose)))
341 const char *strtab;
343 strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
344 _dl_error_printf ("\
345 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
346 rtld_progname ?: "<program name unknown>",
347 strtab + refsym->st_name);
349 memcpy (reloc_addr_arg, (void *) value,
350 MIN (sym->st_size, refsym->st_size));
351 break;
352 case R_SH_GLOB_DAT:
353 case R_SH_JMP_SLOT:
354 /* These addresses are always aligned. */
355 *reloc_addr = value;
356 break;
357 #if !defined RTLD_BOOTSTRAP || USE___THREAD
358 /* XXX Remove TLS relocations which are not needed. */
359 case R_SH_TLS_DTPMOD32:
360 # ifdef RTLD_BOOTSTRAP
361 /* During startup the dynamic linker is always the module
362 with index 1.
363 XXX If this relocation is necessary move before RESOLVE
364 call. */
365 *reloc_addr = 1;
366 # else
367 /* Get the information from the link map returned by the
368 resolv function. */
369 if (sym_map != NULL)
370 *reloc_addr = sym_map->l_tls_modid;
371 # endif
372 break;
373 case R_SH_TLS_DTPOFF32:
374 # ifndef RTLD_BOOTSTRAP
375 /* During relocation all TLS symbols are defined and used.
376 Therefore the offset is already correct. */
377 if (sym != NULL)
378 *reloc_addr = sym->st_value;
379 # endif
380 break;
381 case R_SH_TLS_TPOFF32:
382 /* The offset is positive, afterward from the thread pointer. */
383 # ifdef RTLD_BOOTSTRAP
384 *reloc_addr = map->l_tls_offset + sym->st_value + reloc->r_addend;
385 # else
386 /* We know the offset of object the symbol is contained in.
387 It is a positive value which will be added to the thread
388 pointer. To get the variable position in the TLS block
389 we add the offset from that of the TLS block. */
390 if (sym != NULL)
392 CHECK_STATIC_TLS (map, sym_map);
393 *reloc_addr = sym_map->l_tls_offset + sym->st_value
394 + reloc->r_addend;
396 # endif
397 break;
398 #endif /* use TLS */
399 case R_SH_DIR32:
401 #ifndef RTLD_BOOTSTRAP
402 /* This is defined in rtld.c, but nowhere in the static
403 libc.a; make the reference weak so static programs can
404 still link. This declaration cannot be done when
405 compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP) because
406 rtld.c contains the common defn for _dl_rtld_map, which
407 is incompatible with a weak decl in the same file. */
408 # ifndef SHARED
409 weak_extern (_dl_rtld_map);
410 # endif
411 if (map == &GL(dl_rtld_map))
412 /* Undo the relocation done here during bootstrapping.
413 Now we will relocate it anew, possibly using a
414 binding found in the user program or a loaded library
415 rather than the dynamic linker's built-in definitions
416 used while loading those libraries. */
417 value -= map->l_addr + refsym->st_value + reloc->r_addend;
418 #endif
419 COPY_UNALIGNED_WORD (&value, reloc_addr_arg,
420 (int) reloc_addr_arg & 3);
421 break;
423 case R_SH_REL32:
424 value = (value - (Elf32_Addr) reloc_addr);
425 COPY_UNALIGNED_WORD (&value, reloc_addr_arg,
426 (int) reloc_addr_arg & 3);
427 break;
428 default:
429 _dl_reloc_bad_type (map, r_type, 0);
430 break;
435 auto inline void
436 __attribute__ ((always_inline))
437 elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
438 void *const reloc_addr_arg)
440 Elf32_Addr value;
442 if (reloc->r_addend)
443 value = l_addr + reloc->r_addend;
444 else
446 COPY_UNALIGNED_WORD (reloc_addr_arg, &value, (int) reloc_addr_arg & 3);
447 value += l_addr;
449 COPY_UNALIGNED_WORD (&value, reloc_addr_arg, (int) reloc_addr_arg & 3);
451 #undef COPY_UNALIGNED_WORD
454 auto inline void
455 __attribute__ ((always_inline))
456 elf_machine_lazy_rel (struct link_map *map,
457 Elf32_Addr l_addr, const Elf32_Rela *reloc)
459 Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
460 /* Check for unexpected PLT reloc type. */
461 if (ELF32_R_TYPE (reloc->r_info) == R_SH_JMP_SLOT)
463 if (__builtin_expect (map->l_mach.plt, 0) == 0)
464 *reloc_addr += l_addr;
465 else
466 *reloc_addr =
467 map->l_mach.plt
468 + (((Elf32_Addr) reloc_addr) - map->l_mach.gotplt) * 7;
470 else
471 _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
474 #endif /* RESOLVE_MAP */