/* $NetBSD: ppc_reloc.c,v 1.49 2011/03/25 18:07:06 joerg Exp $ */ /*- * Copyright (C) 1998 Tsubai Masanari * Portions copyright 2002 Charles M. Hannum * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #ifndef lint __RCSID("$NetBSD: ppc_reloc.c,v 1.49 2011/03/25 18:07:06 joerg Exp $"); #endif /* not lint */ #include #include #include #include #include #include #include "debug.h" #include "rtld.h" void _rtld_powerpc_pltcall(Elf_Word); void _rtld_powerpc_pltresolve(Elf_Word, Elf_Word); #define ha(x) ((((u_int32_t)(x) & 0x8000) ? \ ((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16) #define l(x) ((u_int32_t)(x) & 0xffff) void _rtld_bind_bssplt_start(void); void _rtld_bind_secureplt_start(void); void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr); caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); static int _rtld_relocate_plt_object(const Obj_Entry *, const Elf_Rela *, int, Elf_Addr *); /* * The PPC PLT format consists of three sections: * (1) The "pltcall" and "pltresolve" glue code. This is always 18 words. * (2) The code part of the PLT entries. There are 2 words per entry for * up to 8192 entries, then 4 words per entry for any additional entries. * (3) The data part of the PLT entries, comprising a jump table. * This section is half the size of the second section (ie. 1 or 2 words * per entry). */ /* * Setup the plt glue routines (for bss-plt). */ #define PLTCALL_SIZE 20 #define PLTRESOLVE_SIZE 24 void _rtld_setup_pltgot(const Obj_Entry *obj) { /* * Secure-PLT is much more sane. */ if (obj->gotptr != NULL) { obj->gotptr[1] = (Elf_Addr) _rtld_bind_secureplt_start; obj->gotptr[2] = (Elf_Addr) obj; dbg(("obj %s secure-plt gotptr=%p start=%p obj=%p", obj->path, obj->gotptr, (void *) obj->gotptr[1], (void *) obj->gotptr[2])); } else { Elf_Word *pltcall, *pltresolve; Elf_Word *jmptab; int N = obj->pltrelalim - obj->pltrela; /* Entries beyond 8192 take twice as much space. */ if (N > 8192) N += N-8192; dbg(("obj %s bss-plt pltgot=%p jmptab=%u start=%p obj=%p", obj->path, obj->pltgot, 18 + N * 2, _rtld_bind_bssplt_start, obj)); pltcall = obj->pltgot; jmptab = pltcall + 18 + N * 2; memcpy(pltcall, _rtld_powerpc_pltcall, PLTCALL_SIZE); pltcall[1] |= ha(jmptab); pltcall[2] |= l(jmptab); pltresolve = obj->pltgot + 8; memcpy(pltresolve, _rtld_powerpc_pltresolve, PLTRESOLVE_SIZE); pltresolve[0] |= ha(_rtld_bind_bssplt_start); pltresolve[1] |= l(_rtld_bind_bssplt_start); pltresolve[3] |= ha(obj); pltresolve[4] |= l(obj); /* * Invalidate the icache for only the code part of the PLT * (and not the jump table at the end). */ __syncicache(pltcall, (char *)jmptab - (char *)pltcall); } } void _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase) { const Elf_Rela *rela = 0, *relalim; Elf_Addr relasz = 0; Elf_Addr *where; for (; dynp->d_tag != DT_NULL; dynp++) { switch (dynp->d_tag) { case DT_RELA: rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr); break; case DT_RELASZ: relasz = dynp->d_un.d_val; break; } } relalim = (const Elf_Rela *)((const uint8_t *)rela + relasz); for (; rela < relalim; rela++) { where = (Elf_Addr *)(relocbase + rela->r_offset); *where = (Elf_Addr)(relocbase + rela->r_addend); } } int _rtld_relocate_nonplt_objects(Obj_Entry *obj) { const Elf_Rela *rela; for (rela = obj->rela; rela < obj->relalim; rela++) { Elf_Addr *where; const Elf_Sym *def; const Obj_Entry *defobj; Elf_Addr tmp; unsigned long symnum; where = (Elf_Addr *)(obj->relocbase + rela->r_offset); symnum = ELF_R_SYM(rela->r_info); switch (ELF_R_TYPE(rela->r_info)) { #if 1 /* XXX Should not be necessary. */ case R_TYPE(JMP_SLOT): #endif case R_TYPE(NONE): break; case R_TYPE(32): /* word32 S + A */ case R_TYPE(GLOB_DAT): /* word32 S + A */ def = _rtld_find_symdef(symnum, obj, &defobj, false); if (def == NULL) return -1; tmp = (Elf_Addr)(defobj->relocbase + def->st_value + rela->r_addend); if (*where != tmp) *where = tmp; rdbg(("32/GLOB_DAT %s in %s --> %p in %s", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where, defobj->path)); break; case R_TYPE(RELATIVE): /* word32 B + A */ *where = (Elf_Addr)(obj->relocbase + rela->r_addend); rdbg(("RELATIVE in %s --> %p", obj->path, (void *)*where)); break; case R_TYPE(COPY): /* * These are deferred until all other relocations have * been done. All we do here is make sure that the * COPY relocation is not in a shared library. They * are allowed only in executable files. */ if (obj->isdynamic) { _rtld_error( "%s: Unexpected R_COPY relocation in shared library", obj->path); return -1; } rdbg(("COPY (avoid in main)")); break; case R_TYPE(DTPMOD32): def = _rtld_find_symdef(symnum, obj, &defobj, false); if (def == NULL) return -1; *where = (Elf_Addr)defobj->tlsindex; rdbg(("DTPMOD32 %s in %s --> %p in %s", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where, defobj->path)); break; case R_TYPE(DTPREL32): def = _rtld_find_symdef(symnum, obj, &defobj, false); if (def == NULL) return -1; if (!defobj->tls_done && _rtld_tls_offset_allocate(obj)) return -1; *where = (Elf_Addr)(def->st_value + rela->r_addend - TLS_DTV_OFFSET); rdbg(("DTPREL32 %s in %s --> %p in %s", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where, defobj->path)); break; case R_TYPE(TPREL32): def = _rtld_find_symdef(symnum, obj, &defobj, false); if (def == NULL) return -1; if (!defobj->tls_done && _rtld_tls_offset_allocate(obj)) return -1; *where = (Elf_Addr)(def->st_value + rela->r_addend + defobj->tlsoffset - TLS_TP_OFFSET); rdbg(("TPREL32 %s in %s --> %p in %s", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where, defobj->path)); break; default: rdbg(("sym = %lu, type = %lu, offset = %p, " "addend = %p, contents = %p, symbol = %s", symnum, (u_long)ELF_R_TYPE(rela->r_info), (void *)rela->r_offset, (void *)rela->r_addend, (void *)*where, obj->strtab + obj->symtab[symnum].st_name)); _rtld_error("%s: Unsupported relocation type %ld " "in non-PLT relocations", obj->path, (u_long) ELF_R_TYPE(rela->r_info)); return -1; } } return 0; } int _rtld_relocate_plt_lazy(const Obj_Entry *obj) { Elf_Addr * const pltresolve = obj->pltgot + 8; const Elf_Rela *rela; int reloff; for (rela = obj->pltrela, reloff = 0; rela < obj->pltrelalim; rela++, reloff++) { Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset); assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); if (obj->gotptr != NULL) { /* * For now, simply treat then as relative. */ *where += (Elf_Addr)obj->relocbase; } else { int distance; if (reloff < 32768) { /* li r11,reloff */ *where++ = 0x39600000 | reloff; } else { /* lis r11,ha(reloff) */ /* addi r11,l(reloff) */ *where++ = 0x3d600000 | ha(reloff); *where++ = 0x396b0000 | l(reloff); } /* b pltresolve */ distance = (Elf_Addr)pltresolve - (Elf_Addr)where; *where++ = 0x48000000 | (distance & 0x03fffffc); /* * Icache invalidation is not done for each entry here * because we sync the entire code part of the PLT once * in _rtld_setup_pltgot() after all the entries have been * initialized. */ /* __syncicache(where - 3, 12); */ } } return 0; } static int _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, int reloff, Elf_Addr *tp) { Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset); Elf_Addr value; const Elf_Sym *def; const Obj_Entry *defobj; int distance; unsigned long info = rela->r_info; assert(ELF_R_TYPE(info) == R_TYPE(JMP_SLOT)); def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL); if (__predict_false(def == NULL)) return -1; if (__predict_false(def == &_rtld_sym_zero)) return 0; value = (Elf_Addr)(defobj->relocbase + def->st_value); distance = value - (Elf_Addr)where; rdbg(("bind now/fixup in %s --> new=%p", defobj->strtab + def->st_name, (void *)value)); if (obj->gotptr != NULL) { /* * For Secure-PLT we simply replace the entry in GOT with the address * of the routine. */ assert(where >= (Elf_Word *)obj->pltgot); assert(where < (Elf_Word *)obj->pltgot + (obj->pltrelalim - obj->pltrela)); *where = value; } else if (abs(distance) < 32*1024*1024) { /* inside 32MB? */ /* b value # branch directly */ *where = 0x48000000 | (distance & 0x03fffffc); __syncicache(where, 4); } else { Elf_Addr *pltcall, *jmptab; int N = obj->pltrelalim - obj->pltrela; /* Entries beyond 8192 take twice as much space. */ if (N > 8192) N += N-8192; pltcall = obj->pltgot; jmptab = pltcall + 18 + N * 2; jmptab[reloff] = value; if (reloff < 32768) { /* li r11,reloff */ *where++ = 0x39600000 | reloff; } else { #ifdef notyet /* lis r11,ha(value) */ /* addi r11,l(value) */ /* mtctr r11 */ /* bctr */ *where++ = 0x3d600000 | ha(value); *where++ = 0x396b0000 | l(value); *where++ = 0x7d6903a6; *where++ = 0x4e800420; #else /* lis r11,ha(reloff) */ /* addi r11,l(reloff) */ *where++ = 0x3d600000 | ha(reloff); *where++ = 0x396b0000 | l(reloff); #endif } /* b pltcall */ distance = (Elf_Addr)pltcall - (Elf_Addr)where; *where++ = 0x48000000 | (distance & 0x03fffffc); __syncicache(where - 3, 12); } if (tp) *tp = value; return 0; } caddr_t _rtld_bind(const Obj_Entry *obj, Elf_Word reloff) { const Elf_Rela *rela = obj->pltrela + reloff; Elf_Addr new_value; int err; new_value = 0; /* XXX gcc */ _rtld_shared_enter(); err = _rtld_relocate_plt_object(obj, rela, reloff, &new_value); if (err) _rtld_die(); _rtld_shared_exit(); return (caddr_t)new_value; } int _rtld_relocate_plt_objects(const Obj_Entry *obj) { const Elf_Rela *rela; int reloff; for (rela = obj->pltrela, reloff = 0; rela < obj->pltrelalim; rela++, reloff++) { if (_rtld_relocate_plt_object(obj, rela, reloff, NULL) < 0) return -1; } return 0; }