1 /* $NetBSD: mips_reloc.c,v 1.58 2010/01/14 11:57:06 skrll Exp $ */
4 * Copyright 1997 Michael L. Hitch <mhitch@montana.edu>
5 * Portions copyright 2002 Charles M. Hannum <root@ihack.net>
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/types.h>
36 #include <sys/endian.h>
42 #include <machine/sysarch.h>
43 #include <machine/tls.h>
49 #define GOT1_MASK 0x8000000000000000UL
51 #define GOT1_MASK 0x80000000UL
55 * Determine if the second GOT entry is reserved for rtld or if it is
56 * the first "real" GOT entry.
58 * This must be a macro rather than a function so that
59 * _rtld_relocate_nonplt_self doesn't trigger a GOT invocation trying
60 * to use it before the local GOT entries in rtld are adjusted.
63 /* Old binutils uses the 32-bit GOT1 mask value for N64. */
64 #define GOT1_RESERVED_FOR_RTLD(got) \
65 (((got)[1] == 0x80000000) || (got)[1] & GOT1_MASK)
67 #define GOT1_RESERVED_FOR_RTLD(got) ((got)[1] & GOT1_MASK)
71 init_pltgot(Obj_Entry *obj)
73 if (obj->pltgot != NULL) {
74 obj->pltgot[0] = (Elf_Addr) &_rtld_bind_start;
75 if (GOT1_RESERVED_FOR_RTLD(obj->pltgot))
76 obj->pltgot[1] = (Elf_Addr) obj | GOT1_MASK;
81 do_copy_relocations(Obj_Entry *dstobj)
87 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
90 * It is possible for the compiler to emit relocations for unaligned data.
91 * We handle this situation with these inlines.
95 * ELF64 MIPS encodes the relocs uniquely. The first 32-bits of info contain
96 * the symbol index. The top 32-bits contain three relocation types encoded
97 * in big-endian integer with first relocation in LSB. This means for little
98 * endian we have to byte swap that integer (r_type).
100 #define Elf_Sxword Elf64_Sxword
101 #define ELF_R_NXTTYPE_64_P(r_type) ((((r_type) >> 8) & 0xff) == R_TYPE(64))
102 #if BYTE_ORDER == LITTLE_ENDIAN
105 #define ELF_R_SYM(r_info) ((r_info) & 0xffffffff)
106 #define ELF_R_TYPE(r_info) bswap32((r_info) >> 32)
109 #define ELF_R_NXTTYPE_64_P(r_type) (0)
110 #define Elf_Sxword Elf32_Sword
113 static __inline Elf_Sxword
114 load_ptr(void *where, size_t len)
118 if (__predict_true(((uintptr_t)where & (len - 1)) == 0)) {
120 if (len == sizeof(Elf_Sxword))
121 return *(Elf_Sxword *)where;
123 return *(Elf_Sword *)where;
127 #if BYTE_ORDER == LITTLE_ENDIAN
128 (void)memcpy(&val, where, len);
130 #if BYTE_ORDER == BIG_ENDIAN
131 (void)memcpy((uint8_t *)((&val)+1) - len, where, len);
133 return (len == sizeof(Elf_Sxword)) ? val : (Elf_Sword)val;
137 store_ptr(void *where, Elf_Sxword val, size_t len)
139 if (__predict_true(((uintptr_t)where & (len - 1)) == 0)) {
141 if (len == sizeof(Elf_Sxword)) {
142 *(Elf_Sxword *)where = val;
146 *(Elf_Sword *)where = val;
149 #if BYTE_ORDER == LITTLE_ENDIAN
150 (void)memcpy(where, &val, len);
152 #if BYTE_ORDER == BIG_ENDIAN
153 (void)memcpy(where, (const uint8_t *)((&val)+1) - len, len);
158 _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
160 const Elf_Rel *rel = NULL, *rellim;
162 const Elf_Sym *symtab = NULL, *sym;
164 Elf_Addr *got = NULL;
165 Elf_Word local_gotno = 0, symtabno = 0, gotsym = 0;
168 for (; dynp->d_tag != DT_NULL; dynp++) {
169 switch (dynp->d_tag) {
171 rel = (const Elf_Rel *)(relocbase + dynp->d_un.d_ptr);
174 relsz = dynp->d_un.d_val;
177 symtab = (const Elf_Sym *)(relocbase + dynp->d_un.d_ptr);
180 got = (Elf_Addr *)(relocbase + dynp->d_un.d_ptr);
182 case DT_MIPS_LOCAL_GOTNO:
183 local_gotno = dynp->d_un.d_val;
185 case DT_MIPS_SYMTABNO:
186 symtabno = dynp->d_un.d_val;
189 gotsym = dynp->d_un.d_val;
194 i = GOT1_RESERVED_FOR_RTLD(got) ? 2 : 1;
195 /* Relocate the local GOT entries */
197 for (; i < local_gotno; i++) {
201 sym = symtab + gotsym;
202 /* Now do the global GOT entries */
203 for (i = gotsym; i < symtabno; i++) {
204 *got = sym->st_value + relocbase;
209 rellim = (const Elf_Rel *)((caddr_t)rel + relsz);
210 for (; rel < rellim; rel++) {
211 Elf_Word r_symndx, r_type;
213 where = (void *)(relocbase + rel->r_offset);
215 r_symndx = ELF_R_SYM(rel->r_info);
216 r_type = ELF_R_TYPE(rel->r_info);
218 switch (r_type & 0xff) {
219 case R_TYPE(REL32): {
221 ELF_R_NXTTYPE_64_P(r_type)
224 Elf_Sxword old = load_ptr(where, rlen);
225 Elf_Sxword val = old;
227 assert(r_type == R_TYPE(REL32)
228 || r_type == (R_TYPE(REL32)|(R_TYPE(64) << 8)));
230 assert(r_symndx < gotsym);
231 sym = symtab + r_symndx;
232 assert(ELF_ST_BIND(sym->st_info) == STB_LOCAL);
234 dbg("REL32/L(%p) %p -> %p in <self>",
235 where, (void *)old, (void *)val);
236 store_ptr(where, val, rlen);
240 case R_TYPE(GPREL32):
253 _mips_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
255 Elf_Addr *got = obj->pltgot;
257 const Obj_Entry *defobj;
260 RtldLockState lockstate;
262 rlock_acquire(rtld_bind_lock, &lockstate);
263 if (sigsetjmp(lockstate.env, 0) != 0)
264 lock_upgrade(rtld_bind_lock, &lockstate);
266 where = &got[obj->local_gotno + reloff - obj->gotsym];
267 def = find_symdef(reloff, obj, &defobj, SYMLOOK_IN_PLT, NULL,
272 target = (Elf_Addr)(defobj->relocbase + def->st_value);
273 dbg("bind now/fixup at %s sym # %jd in %s --> was=%p new=%p",
275 (intmax_t)reloff, defobj->strtab + def->st_name,
276 (void *)*where, (void *)target);
279 lock_release(rtld_bind_lock, &lockstate);
280 return (Elf_Addr)target;
284 reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
285 RtldLockState *lockstate)
288 const Elf_Rel *rellim;
289 Elf_Addr *got = obj->pltgot;
290 const Elf_Sym *sym, *def;
291 const Obj_Entry *defobj;
293 #ifdef SUPPORT_OLD_BROKEN_LD
297 /* The relocation for the dynamic loader has already been done. */
301 if ((flags & SYMLOOK_IFUNC) != 0)
302 /* XXX not implemented */
305 #ifdef SUPPORT_OLD_BROKEN_LD
308 for (i = 1; i < 12; i++)
309 if (sym[i].st_info == ELF_ST_INFO(STB_LOCAL, STT_NOTYPE))
311 dbg("%s: broken=%d", obj->path, broken);
314 i = GOT1_RESERVED_FOR_RTLD(got) ? 2 : 1;
316 /* Relocate the local GOT entries */
318 dbg("got:%p for %d entries adding %p",
319 got, obj->local_gotno, obj->relocbase);
320 for (; i < obj->local_gotno; i++) {
321 *got += (Elf_Addr)obj->relocbase;
324 sym = obj->symtab + obj->gotsym;
326 dbg("got:%p for %d entries",
328 /* Now do the global GOT entries */
329 for (i = obj->gotsym; i < obj->symtabno; i++) {
330 dbg(" doing got %d sym %p (%s, %lx)", i - obj->gotsym, sym,
331 sym->st_name + obj->strtab, (u_long) *got);
333 #ifdef SUPPORT_OLD_BROKEN_LD
334 if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
335 broken && sym->st_shndx == SHN_UNDEF) {
337 * XXX DANGER WILL ROBINSON!
338 * You might think this is stupid, as it intentionally
339 * defeats lazy binding -- and you'd be right.
340 * Unfortunately, for lazy binding to work right, we
341 * need to a way to force the GOT slots used for
342 * function pointers to be resolved immediately. This
343 * is supposed to be done automatically by the linker,
344 * by not outputting a PLT slot and setting st_value
345 * to 0 if there are non-PLT references, but older
346 * versions of GNU ld do not do this.
348 def = find_symdef(i, obj, &defobj, flags, NULL,
352 *got = def->st_value + (Elf_Addr)defobj->relocbase;
355 if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
356 sym->st_value != 0 && sym->st_shndx == SHN_UNDEF) {
358 * If there are non-PLT references to the function,
359 * st_value should be 0, forcing us to resolve the
360 * address immediately.
362 * XXX DANGER WILL ROBINSON!
363 * The linker is not outputting PLT slots for calls to
364 * functions that are defined in the same shared
365 * library. This is a bug, because it can screw up
366 * link ordering rules if the symbol is defined in
367 * more than one module. For now, if there is a
368 * definition, we fail the test above and force a full
369 * symbol lookup. This means that all intra-module
370 * calls are bound immediately. - mycroft, 2003/09/24
372 *got = sym->st_value + (Elf_Addr)obj->relocbase;
373 if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
374 dbg("Warning2, i:%d maps to relocbase address:%p",
378 } else if (sym->st_info == ELF_ST_INFO(STB_GLOBAL, STT_SECTION)) {
379 /* Symbols with index SHN_ABS are not relocated. */
380 if (sym->st_shndx != SHN_ABS) {
381 *got = sym->st_value +
382 (Elf_Addr)obj->relocbase;
383 if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
384 dbg("Warning3, i:%d maps to relocbase address:%p",
389 /* TODO: add cache here */
390 def = find_symdef(i, obj, &defobj, flags, NULL,
393 dbg("Warning4, can't find symbole %d", i);
396 *got = def->st_value + (Elf_Addr)defobj->relocbase;
397 if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
398 dbg("Warning4, i:%d maps to relocbase address:%p",
400 dbg("via first obj symbol %s",
401 obj->strtab + obj->symtab[i].st_name);
402 dbg("found in obj %p:%s",
403 defobj, defobj->path);
407 dbg(" --> now %lx", (u_long) *got);
413 rellim = (const Elf_Rel *)((caddr_t)obj->rel + obj->relsize);
414 for (rel = obj->rel; rel < rellim; rel++) {
415 Elf_Word r_symndx, r_type;
418 where = obj->relocbase + rel->r_offset;
419 r_symndx = ELF_R_SYM(rel->r_info);
420 r_type = ELF_R_TYPE(rel->r_info);
422 switch (r_type & 0xff) {
426 case R_TYPE(REL32): {
427 /* 32-bit PC-relative reference */
429 ELF_R_NXTTYPE_64_P(r_type)
432 Elf_Sxword old = load_ptr(where, rlen);
433 Elf_Sxword val = old;
435 def = obj->symtab + r_symndx;
437 if (r_symndx >= obj->gotsym) {
438 val += got[obj->local_gotno + r_symndx - obj->gotsym];
439 dbg("REL32/G(%p) %p --> %p (%s) in %s",
440 where, (void *)old, (void *)val,
441 obj->strtab + def->st_name,
445 * XXX: ABI DIFFERENCE!
447 * Old NetBSD binutils would generate shared
448 * libs with section-relative relocations being
449 * already adjusted for the start address of
452 * New binutils, OTOH, generate shared libs
453 * with the same relocations being based at
454 * zero, so we need to add in the start address
461 ELF_ST_INFO(STB_LOCAL, STT_SECTION)
462 #ifdef SUPPORT_OLD_BROKEN_LD
466 val += (Elf_Addr)def->st_value;
468 val += (Elf_Addr)obj->relocbase;
470 dbg("REL32/L(%p) %p -> %p (%s) in %s",
471 where, (void *)old, (void *)val,
472 obj->strtab + def->st_name, obj->path);
474 store_ptr(where, val, rlen);
479 case R_TYPE(TLS_DTPMOD64):
481 case R_TYPE(TLS_DTPMOD32):
485 const size_t rlen = sizeof(Elf_Addr);
486 Elf_Addr old = load_ptr(where, rlen);
489 def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
494 val += (Elf_Addr)defobj->tlsindex;
496 store_ptr(where, val, rlen);
497 dbg("DTPMOD %s in %s %p --> %p in %s",
498 obj->strtab + obj->symtab[r_symndx].st_name,
499 obj->path, (void *)old, (void*)val, defobj->path);
504 case R_TYPE(TLS_DTPREL64):
506 case R_TYPE(TLS_DTPREL32):
509 const size_t rlen = sizeof(Elf_Addr);
510 Elf_Addr old = load_ptr(where, rlen);
513 def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
518 if (!defobj->tls_done && allocate_tls_offset(obj))
521 val += (Elf_Addr)def->st_value - TLS_DTP_OFFSET;
522 store_ptr(where, val, rlen);
524 dbg("DTPREL %s in %s %p --> %p in %s",
525 obj->strtab + obj->symtab[r_symndx].st_name,
526 obj->path, (void*)old, (void *)val, defobj->path);
531 case R_TYPE(TLS_TPREL64):
533 case R_TYPE(TLS_TPREL32):
536 const size_t rlen = sizeof(Elf_Addr);
537 Elf_Addr old = load_ptr(where, rlen);
540 def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
546 if (!defobj->tls_done && allocate_tls_offset(obj))
549 val += (Elf_Addr)(def->st_value + defobj->tlsoffset
550 - TLS_TP_OFFSET - TLS_TCB_SIZE);
551 store_ptr(where, val, rlen);
553 dbg("TPREL %s in %s %p --> %p in %s",
554 obj->strtab + obj->symtab[r_symndx].st_name,
555 obj->path, (void*)old, (void *)val, defobj->path);
562 dbg("sym = %lu, type = %lu, offset = %p, "
563 "contents = %p, symbol = %s",
564 (u_long)r_symndx, (u_long)ELF_R_TYPE(rel->r_info),
565 (void *)rel->r_offset,
566 (void *)load_ptr(where, sizeof(Elf_Sword)),
567 obj->strtab + obj->symtab[r_symndx].st_name);
568 _rtld_error("%s: Unsupported relocation type %ld "
569 "in non-PLT relocations",
570 obj->path, (u_long) ELF_R_TYPE(rel->r_info));
579 * Process the PLT relocations.
582 reloc_plt(Obj_Entry *obj)
585 const Elf_Rel *rellim;
588 dbg("reloc_plt obj:%p pltrel:%p sz:%s", obj, obj->pltrel, (int)obj->pltrelsize);
589 dbg("gottable %p num syms:%s", obj->pltgot, obj->symtabno );
590 dbg("*****************************************************");
591 rellim = (const Elf_Rel *)((char *)obj->pltrel +
593 for (rel = obj->pltrel; rel < rellim; rel++) {
595 where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
596 *where += (Elf_Addr )obj->relocbase;
600 /* PLT fixups were done above in the GOT relocation. */
605 * LD_BIND_NOW was set - force relocation for all jump slots
608 reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate)
611 obj->jmpslots_done = true;
617 reloc_iresolve(Obj_Entry *obj, struct Struct_RtldLockState *lockstate)
620 /* XXX not implemented */
625 reloc_gnu_ifunc(Obj_Entry *obj, int flags,
626 struct Struct_RtldLockState *lockstate)
629 /* XXX not implemented */
634 reloc_jmpslot(Elf_Addr *where, Elf_Addr target, const Obj_Entry *defobj,
635 const Obj_Entry *obj, const Elf_Rel *rel)
644 ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused)
649 allocate_initial_tls(Obj_Entry *objs)
654 * Fix the size of the static TLS block by using the maximum
655 * offset allocated so far and adding a bit for dynamic modules to
658 tls_static_space = tls_last_offset + tls_last_size + RTLD_STATIC_TLS_EXTRA;
660 tls = (char *) allocate_tls(objs, NULL, TLS_TCB_SIZE, 8);
662 sysarch(MIPS_SET_TLS, tls);
671 __asm__ __volatile__ (
678 * XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
680 * Remove the offset since this really a request to get the TLS
681 * pointer via sysarch() (in theory). Of course, this may go away
682 * once the TLS code is rewritten.
684 _rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
696 __asm__ __volatile__ (
703 * XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
705 * Remove the offset since this really a request to get the TLS
706 * pointer via sysarch() (in theory). Of course, this may go away
707 * once the TLS code is rewritten.
709 _rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
713 #endif /* ! __mips_n64 */
716 __tls_get_addr(tls_index* ti)
721 #ifdef TLS_USE_SYSARCH
722 sysarch(MIPS_GET_TLS, &tls);
724 tls = _mips_get_tls();
727 p = tls_get_addr_common(tls, ti->ti_module, ti->ti_offset + TLS_DTP_OFFSET);