/* $NetBSD: mdreloc.c,v 1.42 2008/04/28 20:23:04 martin Exp $ */ /*- * Copyright (c) 2000 Eduardo Horvath. * Copyright (c) 1999 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Paul Kranenburg. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 FOUNDATION OR CONTRIBUTORS * 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 __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include "debug.h" #include "rtld.h" /* * The following table holds for each relocation type: * - the width in bits of the memory location the relocation * applies to (not currently used) * - the number of bits the relocation value must be shifted to the * right (i.e. discard least significant bits) to fit into * the appropriate field in the instruction word. * - flags indicating whether * * the relocation involves a symbol * * the relocation is relative to the current position * * the relocation is for a GOT entry * * the relocation is relative to the load address * */ #define _RF_S 0x80000000 /* Resolve symbol */ #define _RF_A 0x40000000 /* Use addend */ #define _RF_P 0x20000000 /* Location relative */ #define _RF_G 0x10000000 /* GOT offset */ #define _RF_B 0x08000000 /* Load address relative */ #define _RF_U 0x04000000 /* Unaligned */ #define _RF_X 0x02000000 /* Bare symbols, needs proc */ #define _RF_D 0x01000000 /* Use dynamic TLS offset */ #define _RF_O 0x00800000 /* Use static TLS offset */ #define _RF_I 0x00400000 /* Use TLS object ID */ #define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */ #define _RF_RS(s) ( (s) & 0xff) /* right shift */ static const int reloc_target_flags[] = { 0, /* NONE */ _RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* 8 */ _RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* 16 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 32 */ _RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */ _RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(10), /* HI22 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 22 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 13 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* LO10 */ _RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */ _RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */ _RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */ _RF_SZ(32) | _RF_RS(0), /* COPY */ _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* GLOB_DAT */ _RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */ _RF_A| _RF_B| _RF_SZ(64) | _RF_RS(0), /* RELATIVE */ _RF_S|_RF_A| _RF_U| _RF_SZ(32) | _RF_RS(0), /* UA_32 */ _RF_A| _RF_SZ(32) | _RF_RS(0), /* PLT32 */ _RF_A| _RF_SZ(32) | _RF_RS(10), /* HIPLT22 */ _RF_A| _RF_SZ(32) | _RF_RS(0), /* LOPLT10 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT32 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PCPLT22 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT10 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 10 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 11 */ _RF_S|_RF_A|_RF_X| _RF_SZ(64) | _RF_RS(0), /* 64 */ _RF_S|_RF_A|/*extra*/ _RF_SZ(32) | _RF_RS(0), /* OLO10 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(42), /* HH22 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(32), /* HM10 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(10), /* LM22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(42), /* PC_HH22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(32), /* PC_HM10 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC_LM22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP16 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP19 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_JMP */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 7 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 5 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 6 */ _RF_S|_RF_A|_RF_P| _RF_SZ(64) | _RF_RS(0), /* DISP64 */ _RF_A| _RF_SZ(64) | _RF_RS(0), /* PLT64 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(10), /* HIX22 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* LOX10 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(22), /* H44 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(12), /* M44 */ _RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* L44 */ _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* REGISTER */ _RF_S|_RF_A| _RF_U| _RF_SZ(64) | _RF_RS(0), /* UA64 */ _RF_S|_RF_A| _RF_U| _RF_SZ(16) | _RF_RS(0), /* UA16 */ /* TLS */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* GD_HI22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GD_LO10 */ 0, /* GD_ADD */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* GD_CALL */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LDM_HI22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LDM_LO10 */ 0, /* LDM_ADD */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* LDM_CALL */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LDO_HIX22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LDO_LOX10 */ 0, /* LDO_ADD */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* IE_HI22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* IE_LO10 */ 0, /* IE_LD */ 0, /* IE_LDX */ 0, /* IE_ADD */ _RF_S|_RF_A| _RF_O| _RF_SZ(32) | _RF_RS(10), /* LE_HIX22 */ _RF_S|_RF_A| _RF_O| _RF_SZ(32) | _RF_RS(0), /* LE_LOX10 */ _RF_S| _RF_I| _RF_SZ(32) | _RF_RS(0), /* DTPMOD32 */ _RF_S| _RF_I| _RF_SZ(64) | _RF_RS(0), /* DTPMOD64 */ _RF_S|_RF_A| _RF_D| _RF_SZ(32) | _RF_RS(0), /* DTPOFF32 */ _RF_S|_RF_A| _RF_D| _RF_SZ(64) | _RF_RS(0), /* DTPOFF64 */ _RF_S|_RF_A| _RF_O| _RF_SZ(32) | _RF_RS(0), /* TPOFF32 */ _RF_S|_RF_A| _RF_O| _RF_SZ(64) | _RF_RS(0) /* TPOFF64 */ }; #if 0 static const char *const reloc_names[] = { "NONE", "8", "16", "32", "DISP_8", "DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22", "22", "13", "LO10", "GOT10", "GOT13", "GOT22", "PC10", "PC22", "WPLT30", "COPY", "GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32", "PLT32", "HIPLT22", "LOPLT10", "LOPLT10", "PCPLT22", "PCPLT32", "10", "11", "64", "OLO10", "HH22", "HM10", "LM22", "PC_HH22", "PC_HM10", "PC_LM22", "WDISP16", "WDISP19", "GLOB_JMP", "7", "5", "6", "DISP64", "PLT64", "HIX22", "LOX10", "H44", "M44", "L44", "REGISTER", "UA64", "UA16", "GD_HI22", "GD_LO10", "GD_ADD", "GD_CALL", "LDM_HI22", "LDMO10", "LDM_ADD", "LDM_CALL", "LDO_HIX22", "LDO_LOX10", "LDO_ADD", "IE_HI22", "IE_LO10", "IE_LD", "IE_LDX", "IE_ADD", "LE_HIX22", "LE_LOX10", "DTPMOD32", "DTPMOD64", "DTPOFF32", "DTPOFF64", "TPOFF32", "TPOFF64" }; #endif #define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0) #define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0) #define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0) #define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0) #define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0) #define RELOC_BARE_SYMBOL(t) ((reloc_target_flags[t] & _RF_X) != 0) #define RELOC_USE_TLS_DOFF(t) ((reloc_target_flags[t] & _RF_D) != 0) #define RELOC_USE_TLS_OFF(t) ((reloc_target_flags[t] & _RF_O) != 0) #define RELOC_USE_TLS_ID(t) ((reloc_target_flags[t] & _RF_I) != 0) #define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff) #define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff) static const long reloc_target_bitmask[] = { #define _BM(x) (~(-(1ULL << (x)))) 0, /* NONE */ _BM(8), _BM(16), _BM(32), /* 8, 16, 32 */ _BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */ _BM(30), _BM(22), /* WDISP30, WDISP22 */ _BM(22), _BM(22), /* HI22, 22 */ _BM(13), _BM(10), /* 13, LO10 */ _BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */ _BM(10), _BM(22), /* PC10, PC22 */ _BM(30), 0, /* WPLT30, COPY */ _BM(32), _BM(32), _BM(32), /* GLOB_DAT, JMP_SLOT, RELATIVE */ _BM(32), _BM(32), /* UA32, PLT32 */ _BM(22), _BM(10), /* HIPLT22, LOPLT10 */ _BM(32), _BM(22), _BM(10), /* PCPLT32, PCPLT22, PCPLT10 */ _BM(10), _BM(11), -1, /* 10, 11, 64 */ _BM(13), _BM(22), /* OLO10, HH22 */ _BM(10), _BM(22), /* HM10, LM22 */ _BM(22), _BM(10), _BM(22), /* PC_HH22, PC_HM10, PC_LM22 */ _BM(16), _BM(19), /* WDISP16, WDISP19 */ -1, /* GLOB_JMP */ _BM(7), _BM(5), _BM(6), /* 7, 5, 6 */ -1, -1, /* DISP64, PLT64 */ _BM(22), _BM(13), /* HIX22, LOX10 */ _BM(22), _BM(10), _BM(13), /* H44, M44, L44 */ -1, -1, _BM(16), /* REGISTER, UA64, UA16 */ _BM(22), _BM(10), 0, _BM(30), /* GD_HI22, GD_LO10, GD_ADD, GD_CALL */ _BM(22), _BM(10), 0, /* LDM_HI22, LDMO10, LDM_ADD */ _BM(30), /* LDM_CALL */ _BM(22), _BM(10), 0, /* LDO_HIX22, LDO_LOX10, LDO_ADD */ _BM(22), _BM(10), 0, 0, /* IE_HI22, IE_LO10, IE_LD, IE_LDX */ 0, /* IE_ADD */ _BM(22), _BM(13), /* LE_HIX22, LE_LOX10 */ _BM(32), -1, /* DTPMOD32, DTPMOD64 */ _BM(32), -1, /* DTPOFF32, DTPOFF64 */ _BM(32), -1 /* TPOFF32, TPOFF64 */ #undef _BM }; #define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t]) #undef flush #define flush(va, offs) \ __asm __volatile("flush %0 + %1" : : "r" (va), "I" (offs)); static int reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, SymCache *cache, int flags, RtldLockState *lockstate); static void install_plt(Elf_Word *pltgot, Elf_Addr proc); extern char _rtld_bind_start_0[]; extern char _rtld_bind_start_1[]; int do_copy_relocations(Obj_Entry *dstobj) { const Elf_Rela *relalim; const Elf_Rela *rela; const Elf_Sym *dstsym; const Elf_Sym *srcsym; void *dstaddr; const void *srcaddr; const Obj_Entry *srcobj, *defobj; SymLook req; const char *name; size_t size; int res; assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */ relalim = (const Elf_Rela *)((caddr_t)dstobj->rela + dstobj->relasize); for (rela = dstobj->rela; rela < relalim; rela++) { if (ELF_R_TYPE(rela->r_info) == R_SPARC_COPY) { dstaddr = (void *)(dstobj->relocbase + rela->r_offset); dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info); name = dstobj->strtab + dstsym->st_name; size = dstsym->st_size; symlook_init(&req, name); req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info)); req.flags = SYMLOOK_EARLY; for (srcobj = globallist_next(dstobj); srcobj != NULL; srcobj = globallist_next(srcobj)) { res = symlook_obj(&req, srcobj); if (res == 0) { srcsym = req.sym_out; defobj = req.defobj_out; break; } } if (srcobj == NULL) { _rtld_error("Undefined symbol \"%s\"" "referenced from COPY relocation" "in %s", name, dstobj->path); return (-1); } srcaddr = (const void *)(defobj->relocbase + srcsym->st_value); memcpy(dstaddr, srcaddr, size); } } return (0); } int reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags, RtldLockState *lockstate) { const Elf_Rela *relalim; const Elf_Rela *rela; SymCache *cache; int r = -1; if ((flags & SYMLOOK_IFUNC) != 0) /* XXX not implemented */ return (0); /* * The dynamic loader may be called from a thread, we have * limited amounts of stack available so we cannot use alloca(). */ if (obj != obj_rtld) { cache = calloc(obj->dynsymcount, sizeof(SymCache)); /* No need to check for NULL here */ } else cache = NULL; relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize); for (rela = obj->rela; rela < relalim; rela++) { if (reloc_nonplt_object(obj, rela, cache, flags, lockstate) < 0) goto done; } r = 0; done: if (cache != NULL) free(cache); return (r); } static int reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, SymCache *cache, int flags, RtldLockState *lockstate) { const Obj_Entry *defobj; const Elf_Sym *def; Elf_Addr *where; Elf_Word *where32; Elf_Word type; Elf_Addr value; Elf_Addr mask; where = (Elf_Addr *)(obj->relocbase + rela->r_offset); where32 = (Elf_Word *)where; defobj = NULL; def = NULL; type = ELF64_R_TYPE_ID(rela->r_info); if (type == R_SPARC_NONE) return (0); /* We do JMP_SLOTs below. */ if (type == R_SPARC_JMP_SLOT) return (0); /* COPY relocs are also handled elsewhere. */ if (type == R_SPARC_COPY) return (0); /* Ignore ADD and CALL relocations for dynamic TLS references. */ if (type == R_SPARC_TLS_GD_ADD || type == R_SPARC_TLS_GD_CALL || type == R_SPARC_TLS_LDM_ADD || type == R_SPARC_TLS_LDM_CALL || type == R_SPARC_TLS_LDO_ADD) return (0); /* * Note: R_SPARC_TLS_TPOFF64 must be the numerically largest * relocation type. */ if (type >= sizeof(reloc_target_bitmask) / sizeof(*reloc_target_bitmask)) { _rtld_error("%s: Unsupported relocation type %d in non-PLT " "object\n", obj->path, type); return (-1); } value = rela->r_addend; /* * Handle relative relocs here, because we might not be able to access * globals yet. */ if (type == R_SPARC_RELATIVE) { /* XXXX -- apparently we ignore the preexisting value. */ *where = (Elf_Addr)(obj->relocbase + value); return (0); } /* * If we get here while relocating rtld itself, we will crash because * a non-local variable is accessed. */ if (RELOC_RESOLVE_SYMBOL(type)) { /* Find the symbol. */ def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, flags, cache, lockstate); if (def == NULL) return (-1); if (RELOC_USE_TLS_ID(type)) value = (Elf_Addr)defobj->tlsindex; else if (RELOC_USE_TLS_DOFF(type)) value += (Elf_Addr)def->st_value; else if (RELOC_USE_TLS_OFF(type)) { /* * We lazily allocate offsets for static TLS as we * see the first relocation that references the TLS * block. This allows us to support (small amounts * of) static TLS in dynamically loaded modules. If * we run out of space, we generate an error. */ if (!defobj->tls_done && !allocate_tls_offset((Obj_Entry*)defobj)) { _rtld_error("%s: No space available for " "static Thread Local Storage", obj->path); return (-1); } value += (Elf_Addr)(def->st_value - defobj->tlsoffset); } else { /* Add in the symbol's absolute address. */ value += (Elf_Addr)(def->st_value + defobj->relocbase); } } if (type == R_SPARC_OLO10) value = (value & 0x3ff) + ELF64_R_TYPE_DATA(rela->r_info); if (type == R_SPARC_HIX22 || type == R_SPARC_TLS_LE_HIX22) value ^= 0xffffffffffffffff; if (RELOC_PC_RELATIVE(type)) value -= (Elf_Addr)where; if (RELOC_BASE_RELATIVE(type)) { /* * Note that even though sparcs use `Elf_rela' exclusively * we still need the implicit memory addend in relocations * referring to GOT entries. Undoubtedly, someone f*cked * this up in the distant past, and now we're stuck with * it in the name of compatibility for all eternity ... * * In any case, the implicit and explicit should be mutually * exclusive. We provide a check for that here. */ /* XXXX -- apparently we ignore the preexisting value */ value += (Elf_Addr)(obj->relocbase); } mask = RELOC_VALUE_BITMASK(type); value >>= RELOC_VALUE_RIGHTSHIFT(type); value &= mask; if (type == R_SPARC_LOX10 || type == R_SPARC_TLS_LE_LOX10) value |= 0x1c00; if (RELOC_UNALIGNED(type)) { /* Handle unaligned relocations. */ Elf_Addr tmp; char *ptr; int size; int i; size = RELOC_TARGET_SIZE(type) / 8; ptr = (char *)where; tmp = 0; /* Read it in one byte at a time. */ for (i = 0; i < size; i++) tmp = (tmp << 8) | ptr[i]; tmp &= ~mask; tmp |= value; /* Write it back out. */ for (i = 0; i < size; i++) ptr[i] = ((tmp >> ((size - i - 1) * 8)) & 0xff); } else if (RELOC_TARGET_SIZE(type) > 32) { *where &= ~mask; *where |= value; } else { *where32 &= ~mask; *where32 |= value; } return (0); } int reloc_plt(Obj_Entry *obj) { #if 0 const Obj_Entry *defobj; const Elf_Rela *relalim; const Elf_Rela *rela; const Elf_Sym *def; Elf_Addr *where; Elf_Addr value; relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); for (rela = obj->pltrela; rela < relalim; rela++) { if (rela->r_addend == 0) continue; assert(ELF64_R_TYPE_ID(rela->r_info) == R_SPARC_JMP_SLOT); where = (Elf_Addr *)(obj->relocbase + rela->r_offset); def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, SYMLOOK_IN_PLT, NULL, lockstate); value = (Elf_Addr)(defobj->relocbase + def->st_value); *where = value; } #endif return (0); } /* * Instruction templates: */ #define BAA 0x10400000 /* ba,a %xcc, 0 */ #define SETHI 0x03000000 /* sethi %hi(0), %g1 */ #define JMP 0x81c06000 /* jmpl %g1+%lo(0), %g0 */ #define NOP 0x01000000 /* sethi %hi(0), %g0 */ #define OR 0x82806000 /* or %g1, 0, %g1 */ #define XOR 0x82c06000 /* xor %g1, 0, %g1 */ #define MOV71 0x8283a000 /* or %o7, 0, %g1 */ #define MOV17 0x9c806000 /* or %g1, 0, %o7 */ #define CALL 0x40000000 /* call 0 */ #define SLLX 0x8b407000 /* sllx %g1, 0, %g1 */ #define SETHIG5 0x0b000000 /* sethi %hi(0), %g5 */ #define ORG5 0x82804005 /* or %g1, %g5, %g1 */ /* %hi(v) with variable shift */ #define HIVAL(v, s) (((v) >> (s)) & 0x003fffff) #define LOVAL(v) ((v) & 0x000003ff) int reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate) { const Obj_Entry *defobj; const Elf_Rela *relalim; const Elf_Rela *rela; const Elf_Sym *def; Elf_Addr *where; Elf_Addr target; relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); for (rela = obj->pltrela; rela < relalim; rela++) { assert(ELF64_R_TYPE_ID(rela->r_info) == R_SPARC_JMP_SLOT); where = (Elf_Addr *)(obj->relocbase + rela->r_offset); def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, SYMLOOK_IN_PLT | flags, NULL, lockstate); if (def == NULL) return -1; target = (Elf_Addr)(defobj->relocbase + def->st_value); reloc_jmpslot(where, target, defobj, obj, (Elf_Rel *)rela); } obj->jmpslots_done = true; return (0); } int reloc_iresolve(Obj_Entry *obj, struct Struct_RtldLockState *lockstate) { /* XXX not implemented */ return (0); } int reloc_gnu_ifunc(Obj_Entry *obj, int flags, struct Struct_RtldLockState *lockstate) { /* XXX not implemented */ return (0); } Elf_Addr reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target, const Obj_Entry *obj, const Obj_Entry *refobj, const Elf_Rel *rel) { const Elf_Rela *rela = (const Elf_Rela *)rel; Elf_Addr offset; Elf_Word *where; if (rela - refobj->pltrela < 32764) { /* * At the PLT entry pointed at by `where', we now construct * a direct transfer to the now fully resolved function * address. * * A PLT entry is supposed to start by looking like this: * * sethi (. - .PLT0), %g1 * ba,a %xcc, .PLT1 * nop * nop * nop * nop * nop * nop * * When we replace these entries we start from the second * entry and do it in reverse order so the last thing we * do is replace the branch. That allows us to change this * atomically. * * We now need to find out how far we need to jump. We * have a choice of several different relocation techniques * which are increasingly expensive. */ where = (Elf_Word *)wherep; offset = ((Elf_Addr)where) - target; if (offset <= (1L<<20) && offset >= -(1L<<20)) { /* * We're within 1MB -- we can use a direct branch * instruction. * * We can generate this pattern: * * sethi %hi(. - .PLT0), %g1 * ba,a %xcc, addr * nop * nop * nop * nop * nop * nop * */ where[1] = BAA | ((offset >> 2) &0x3fffff); flush(where, 4); } else if (target >= 0 && target < (1L<<32)) { /* * We're within 32-bits of address zero. * * The resulting code in the jump slot is: * * sethi %hi(. - .PLT0), %g1 * sethi %hi(addr), %g1 * jmp %g1+%lo(addr) * nop * nop * nop * nop * nop * */ where[2] = JMP | LOVAL(target); flush(where, 8); where[1] = SETHI | HIVAL(target, 10); flush(where, 4); } else if (target <= 0 && target > -(1L<<32)) { /* * We're within 32-bits of address -1. * * The resulting code in the jump slot is: * * sethi %hi(. - .PLT0), %g1 * sethi %hix(addr), %g1 * xor %g1, %lox(addr), %g1 * jmp %g1 * nop * nop * nop * nop * */ where[3] = JMP; flush(where, 12); where[2] = XOR | ((~target) & 0x00001fff); flush(where, 8); where[1] = SETHI | HIVAL(~target, 10); flush(where, 4); } else if (offset <= (1L<<32) && offset >= -((1L<<32) - 4)) { /* * We're within 32-bits -- we can use a direct call * insn * * The resulting code in the jump slot is: * * sethi %hi(. - .PLT0), %g1 * mov %o7, %g1 * call (.+offset) * mov %g1, %o7 * nop * nop * nop * nop * */ where[3] = MOV17; flush(where, 12); where[2] = CALL | ((offset >> 4) & 0x3fffffff); flush(where, 8); where[1] = MOV71; flush(where, 4); } else if (offset >= 0 && offset < (1L<<44)) { /* * We're within 44 bits. We can generate this * pattern: * * The resulting code in the jump slot is: * * sethi %hi(. - .PLT0), %g1 * sethi %h44(addr), %g1 * or %g1, %m44(addr), %g1 * sllx %g1, 12, %g1 * jmp %g1+%l44(addr) * nop * nop * nop * */ where[4] = JMP | LOVAL(offset); flush(where, 16); where[3] = SLLX | 12; flush(where, 12); where[2] = OR | (((offset) >> 12) & 0x00001fff); flush(where, 8); where[1] = SETHI | HIVAL(offset, 22); flush(where, 4); } else if (offset < 0 && offset > -(1L<<44)) { /* * We're within 44 bits. We can generate this * pattern: * * The resulting code in the jump slot is: * * sethi %hi(. - .PLT0), %g1 * sethi %h44(-addr), %g1 * xor %g1, %m44(-addr), %g1 * sllx %g1, 12, %g1 * jmp %g1+%l44(addr) * nop * nop * nop * */ where[4] = JMP | LOVAL(offset); flush(where, 16); where[3] = SLLX | 12; flush(where, 12); where[2] = XOR | (((~offset) >> 12) & 0x00001fff); flush(where, 8); where[1] = SETHI | HIVAL(~offset, 22); flush(where, 4); } else { /* * We need to load all 64-bits * * The resulting code in the jump slot is: * * sethi %hi(. - .PLT0), %g1 * sethi %hh(addr), %g1 * sethi %lm(addr), %g5 * or %g1, %hm(addr), %g1 * sllx %g1, 32, %g1 * or %g1, %g5, %g1 * jmp %g1+%lo(addr) * nop * */ where[6] = JMP | LOVAL(target); flush(where, 24); where[5] = ORG5; flush(where, 20); where[4] = SLLX | 32; flush(where, 16); where[3] = OR | LOVAL((target) >> 32); flush(where, 12); where[2] = SETHIG5 | HIVAL(target, 10); flush(where, 8); where[1] = SETHI | HIVAL(target, 42); flush(where, 4); } } else { /* * This is a high PLT slot; the relocation offset specifies a * pointer that needs to be frobbed; no actual code needs to * be modified. The pointer to be calculated needs the addend * added and the reference object relocation base subtraced. */ *wherep = target + rela->r_addend - (Elf_Addr)refobj->relocbase; } return (target); } void ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused) { } /* * Install rtld function call into this PLT slot. */ #define SAVE 0x9de3bf50 #define SETHI_l0 0x21000000 #define SETHI_l1 0x23000000 #define OR_l0_l0 0xa0142000 #define SLLX_l0_32_l0 0xa12c3020 #define OR_l0_l1_l0 0xa0140011 #define JMPL_l0_o1 0x93c42000 #define MOV_g1_o0 0x90100001 void init_pltgot(Obj_Entry *obj) { Elf_Word *entry; if (obj->pltgot != NULL) { entry = (Elf_Word *)obj->pltgot; install_plt(&entry[0], (Elf_Addr)_rtld_bind_start_0); install_plt(&entry[8], (Elf_Addr)_rtld_bind_start_1); obj->pltgot[8] = (Elf_Addr)obj; } } static void install_plt(Elf_Word *pltgot, Elf_Addr proc) { pltgot[0] = SAVE; flush(pltgot, 0); pltgot[1] = SETHI_l0 | HIVAL(proc, 42); flush(pltgot, 4); pltgot[2] = SETHI_l1 | HIVAL(proc, 10); flush(pltgot, 8); pltgot[3] = OR_l0_l0 | LOVAL((proc) >> 32); flush(pltgot, 12); pltgot[4] = SLLX_l0_32_l0; flush(pltgot, 16); pltgot[5] = OR_l0_l1_l0; flush(pltgot, 20); pltgot[6] = JMPL_l0_o1 | LOVAL(proc); flush(pltgot, 24); pltgot[7] = MOV_g1_o0; flush(pltgot, 28); } void allocate_initial_tls(Obj_Entry *objs) { Elf_Addr* tpval; /* * Fix the size of the static TLS block by using the maximum offset * allocated so far and adding a bit for dynamic modules to use. */ tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA; tpval = allocate_tls(objs, NULL, 3 * sizeof(Elf_Addr), sizeof(Elf_Addr)); __asm __volatile("mov %0, %%g7" : : "r" (tpval)); } void *__tls_get_addr(tls_index *ti) { register Elf_Addr** tp __asm__("%g7"); return (tls_get_addr_common(tp, ti->ti_module, ti->ti_offset)); }