diff options
Diffstat (limited to 'libexec/ld.so/arm/rtld_machine.c')
| -rw-r--r-- | libexec/ld.so/arm/rtld_machine.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/libexec/ld.so/arm/rtld_machine.c b/libexec/ld.so/arm/rtld_machine.c new file mode 100644 index 00000000000..de652c63a80 --- /dev/null +++ b/libexec/ld.so/arm/rtld_machine.c @@ -0,0 +1,435 @@ +/* $OpenBSD: rtld_machine.c,v 1.1 2004/02/07 06:00:49 drahn Exp $ */ + +/* + * Copyright (c) 2004 Dale Rahn + * + * 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 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. + * + */ + +#define _DYN_LOADER + +#include <sys/types.h> +#include <sys/mman.h> + +#include <nlist.h> +#include <link.h> +#include <signal.h> + +#include "syscall.h" +#include "archdep.h" +#include "resolve.h" + +void _dl_bind_start(void); /* XXX */ +Elf_Addr _dl_bind(elf_object_t *object, int reloff); +#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_E 0x02000000 /* ERROR */ +#define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */ +#define _RF_RS(s) ((s) & 0xff) /* right shift */ +static int reloc_target_flags[] = { + 0, /* 0 NONE */ + _RF_S|_RF_P|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 1 PC24 */ + _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 2 ABS32 */ + _RF_S|_RF_P|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 3 REL32 */ + _RF_S|_RF_P|_RF_A| _RF_E, /* 4 REL13 */ + _RF_S|_RF_A| _RF_E, /* 5 ABS16 */ + _RF_S|_RF_A| _RF_E, /* 6 ABS12 */ + _RF_S|_RF_A| _RF_E, /* 7 T_ABS5 */ + _RF_S|_RF_A| _RF_E, /* 8 ABS8 */ + _RF_S|_RF_B|_RF_A| _RF_E, /* 9 SBREL32 */ + _RF_S|_RF_P|_RF_A| _RF_E, /* 10 T_PC22 */ + _RF_S|_RF_P|_RF_A| _RF_E, /* 11 T_PC8 */ + _RF_E, /* 12 Reserved */ + _RF_S|_RF_A| _RF_E, /* 13 SWI24 */ + _RF_S|_RF_A| _RF_E, /* 14 T_SWI8 */ + _RF_E, /* 15 OBSL */ + _RF_E, /* 16 OBSL */ + _RF_E, /* 17 UNUSED */ + _RF_E, /* 18 UNUSED */ + _RF_E, /* 19 UNUSED */ + _RF_S| _RF_SZ(32) | _RF_RS(0), /* 20 COPY */ + _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 21 GLOB_DAT */ + _RF_S| _RF_SZ(32) | _RF_RS(0), /* 22 JUMP_SLOT */ + _RF_A| _RF_B| _RF_SZ(32) | _RF_RS(0), /* 23 RELATIVE */ + _RF_E, /* 24 GOTOFF */ + _RF_E, /* 25 GOTPC */ + _RF_E, /* 26 GOT32 */ + _RF_E, /* 27 PLT32 */ + _RF_E, /* 28 UNUSED */ + _RF_E, /* 29 UNUSED */ + _RF_E, /* 30 UNUSED */ + _RF_E, /* 31 UNUSED */ + _RF_E, /* 32 A_PCR 0 */ + _RF_E, /* 33 A_PCR 8 */ + _RF_E, /* 34 A_PCR 16 */ + _RF_E, /* 35 B_PCR 0 */ + _RF_E, /* 36 B_PCR 12 */ + _RF_E, /* 37 B_PCR 20 */ + _RF_E, /* 38 RELAB32 */ + _RF_E, /* 39 ROSGREL32 */ + _RF_E, /* 40 V4BX */ + _RF_E, /* 41 STKCHK */ + _RF_E /* 42 TSTKCHK */ +}; + +#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_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff) +#define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff) +static int reloc_target_bitmask[] = { +#define _BM(x) (x == 32? ~0 : ~(-(1UL << (x)))) + _BM(0), /* 0 NONE */ + _BM(24), /* 1 PC24 */ + _BM(32), /* 2 ABS32 */ + _BM(32), /* 3 REL32 */ + _BM(0), /* 4 REL13 */ + _BM(0), /* 5 ABS16 */ + _BM(0), /* 6 ABS12 */ + _BM(0), /* 7 T_ABS5 */ + _BM(0), /* 8 ABS8 */ + _BM(32), /* 9 SBREL32 */ + _BM(0), /* 10 T_PC22 */ + _BM(0), /* 11 T_PC8 */ + _BM(0), /* 12 Reserved */ + _BM(0), /* 13 SWI24 */ + _BM(0), /* 14 T_SWI8 */ + _BM(0), /* 15 OBSL */ + _BM(0), /* 16 OBSL */ + _BM(0), /* 17 UNUSED */ + _BM(0), /* 18 UNUSED */ + _BM(0), /* 19 UNUSED */ + _BM(32), /* 20 COPY */ + _BM(32), /* 21 GLOB_DAT */ + _BM(32), /* 22 JUMP_SLOT */ + _BM(32), /* 23 RELATIVE */ + _BM(0), /* 24 GOTOFF */ + _BM(0), /* 25 GOTPC */ + _BM(0), /* 26 GOT32 */ + _BM(0), /* 27 PLT32 */ + _BM(0), /* 28 UNUSED */ + _BM(0), /* 29 UNUSED */ + _BM(0), /* 30 UNUSED */ + _BM(0), /* 31 UNUSED */ + _BM(0), /* 32 A_PCR 0 */ + _BM(0), /* 33 A_PCR 8 */ + _BM(0), /* 34 A_PCR 16 */ + _BM(0), /* 35 B_PCR 0 */ + _BM(0), /* 36 B_PCR 12 */ + _BM(0), /* 37 B_PCR 20 */ + _BM(0), /* 38 RELAB32 */ + _BM(0), /* 39 ROSGREL32 */ + _BM(0), /* 40 V4BX */ + _BM(0), /* 41 STKCHK */ + _BM(0) /* 42 TSTKCHK */ +#undef _BM +}; +#define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t]) + +void +_dl_bcopy(const void *src, void *dest, int size) +{ + unsigned const char *psrc = src; + unsigned char *pdest = dest; + int i; + + for (i = 0; i < size; i++) + pdest[i] = psrc[i]; +} + +#define R_TYPE(x) R_ARM_ ## x + +void _dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_Rel *rel); + +#define LD_PROTECT_TEXT +int +_dl_md_reloc(elf_object_t *object, int rel, int relsz) +{ + long i; + long numrel; + long fails = 0; + Elf_Addr loff; + Elf_Rel *rels; +#ifndef LD_PROTECT_TEXT + struct load_list *llist; +#endif + + loff = object->load_offs; + numrel = object->Dyn.info[relsz] / sizeof(Elf_Rel); + rels = (Elf_Rel *)(object->Dyn.info[rel]); + + if (rels == NULL) + return(0); + +#ifndef LD_PROTECT_TEXT + /* + * unprotect some segments if we need it. + */ + if ((rel == DT_REL || rel == DT_RELA)) { + for (llist = object->load_list; llist != NULL; llist = llist->next) { + if (!(llist->prot & PROT_WRITE)) + _dl_mprotect(llist->start, llist->size, + llist->prot|PROT_WRITE); + } + } +#endif + + for (i = 0; i < numrel; i++, rels++) { + Elf_Addr *where, value, ooff, mask; + Elf_Word type; + const Elf_Sym *sym, *this; + const char *symn; + + type = ELF_R_TYPE(rels->r_info); + + if (reloc_target_flags[type] & _RF_E) { + _dl_printf(" bad relocation %d %d\n", i, type); + _dl_exit(1); + } + if (type == R_TYPE(NONE)) + continue; + + if (type == R_TYPE(JUMP_SLOT) && rel != DT_JMPREL) + continue; + + where = (Elf_Addr *)(rels->r_offset + loff); + + if (RELOC_USE_ADDEND(type)) +#ifdef LDSO_ARCH_IS_RELA_ + value = rels->r_addend; +#else + value = *where & RELOC_VALUE_BITMASK(type); +#endif + else + value = 0; + + sym = NULL; + symn = NULL; + if (RELOC_RESOLVE_SYMBOL(type)) { + sym = object->dyn.symtab; + sym += ELF_R_SYM(rels->r_info); + symn = object->dyn.strtab + sym->st_name; + + if (sym->st_shndx != SHN_UNDEF && + ELF_ST_BIND(sym->st_info) == STB_LOCAL) { + value += loff; + } else { + this = NULL; + ooff = _dl_find_symbol_bysym(object, + ELF_R_SYM(rels->r_info), + _dl_objects, &this, + SYM_SEARCH_ALL|SYM_WARNNOTFOUND| + ((type == R_TYPE(JUMP_SLOT)) ? + SYM_PLT : SYM_NOTPLT), + sym->st_size); + if (this == NULL) { +resolve_failed: + _dl_printf("%s: %s: can't resolve " + "reference '%s'\n", + _dl_progname, object->load_name, + symn); + fails++; + continue; + } + value += (Elf_Addr)(ooff + this->st_value); + } + } + + if (type == R_TYPE(JUMP_SLOT)) { + /* + _dl_reloc_plt((Elf_Word *)where, value, rels); + */ + *where = value; + continue; + } + + if (type == R_TYPE(COPY)) { + void *dstaddr = where; + const void *srcaddr; + const Elf_Sym *dstsym = sym, *srcsym = NULL; + size_t size = dstsym->st_size; + Elf_Addr soff; + + soff = _dl_find_symbol(symn, object->next, &srcsym, + SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_NOTPLT, + size, object); + if (srcsym == NULL) + goto resolve_failed; + + srcaddr = (void *)(soff + srcsym->st_value); + _dl_bcopy(srcaddr, dstaddr, size); + continue; + } + + if (RELOC_PC_RELATIVE(type)) + value -= (Elf_Addr)where; + if (RELOC_BASE_RELATIVE(type)) + value += loff; + + mask = RELOC_VALUE_BITMASK(type); + value >>= RELOC_VALUE_RIGHTSHIFT(type); + value &= mask; + + if (RELOC_UNALIGNED(type)) { + /* Handle unaligned relocations. */ + Elf_Addr tmp = 0; + char *ptr = (char *)where; + int i, size = RELOC_TARGET_SIZE(type)/8; + + /* 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 >> (8*i)) & 0xff); + } else { + *where &= ~mask; + *where |= value; + } + } + +#ifndef LD_PROTECT_TEXT + /* reprotect the unprotected segments */ + if ((rel == DT_REL || rel == DT_RELA)) { + for (llist = object->load_list; llist != NULL; llist = llist->next) { + if (!(llist->prot & PROT_WRITE)) + _dl_mprotect(llist->start, llist->size, + llist->prot); + } + } + #endif + + return (fails); +} + +/* + * Relocate the Global Offset Table (GOT). + * This is done by calling _dl_md_reloc on DT_JUMPREL for DL_BIND_NOW, + * otherwise the lazy binding plt initialization is performed. + */ +void +_dl_md_reloc_got(elf_object_t *object, int lazy) +{ + Elf_Addr *pltgot = (Elf_Addr *)object->Dyn.info[DT_PLTGOT]; + Elf_Addr ooff; + Elf_Addr plt_addr; + const Elf_Sym *this; + + if (object->Dyn.info[DT_PLTREL] != DT_REL) + return; + + object->got_addr = NULL; + object->got_size = 0; + this = NULL; + ooff = _dl_find_symbol("__got_start", object, &this, + SYM_SEARCH_SELF|SYM_NOWARNNOTFOUND|SYM_PLT, 0, object); + if (this != NULL) + object->got_addr = ooff + this->st_value; + + this = NULL; + ooff = _dl_find_symbol("__got_end", object, &this, + SYM_SEARCH_SELF|SYM_NOWARNNOTFOUND|SYM_PLT, 0, object); + if (this != NULL) + object->got_size = ooff + this->st_value - object->got_addr; + + plt_addr = 0; + object->plt_size = 0; + this = NULL; + ooff = _dl_find_symbol("__plt_start", object, &this, + SYM_SEARCH_SELF|SYM_NOWARNNOTFOUND|SYM_PLT, 0, object); + if (this != NULL) + plt_addr = ooff + this->st_value; + + if (object->got_addr == NULL) + object->got_start = NULL; + else { + object->got_start = ELF_TRUNC(object->got_addr, _dl_pagesz); + object->got_size += object->got_addr - object->got_start; + object->got_size = ELF_ROUND(object->got_size, _dl_pagesz); + } +#if 1 + object->plt_start = NULL; +#else + if (plt_addr == NULL) + object->plt_start = NULL; + else { + object->plt_start = ELF_TRUNC(plt_addr, _dl_pagesz); + object->plt_size += plt_addr - object->plt_start; + object->plt_size = ELF_ROUND(object->plt_size, _dl_pagesz); + } +#endif + + if (!lazy) { + _dl_md_reloc(object, DT_JMPREL, DT_PLTRELSZ); + } else { + pltgot[1] = (Elf_Addr)object; + pltgot[2] = (Elf_Addr)_dl_bind_start; + } + if (object->got_size != 0) + _dl_mprotect((void*)object->got_addr, object->got_size, + PROT_READ); + if (object->plt_size != 0) + _dl_mprotect((void*)object->plt_start, object->plt_size, + PROT_READ|PROT_EXEC); +} + +Elf_Addr +_dl_bind(elf_object_t *object, int reloff) +{ + const Elf_Sym *sym, *this; + Elf_Addr *r_addr, ooff, newval; + const char *symn; + Elf_Rel *rels; + + rels = ((Elf_Rel *)object->Dyn.info[DT_JMPREL]) + (reloff>>2); + + sym = object->dyn.symtab; + sym += ELF_R_SYM(rels->r_info); + symn = object->dyn.strtab + sym->st_name; + + ooff = _dl_find_symbol(symn, _dl_objects, &this, + SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT, sym->st_size, object); + if (this == NULL) { + _dl_printf("lazy binding failed!\n"); + *((int *)0) = 0; /* XXX */ + } + + r_addr = (Elf_Addr *)(object->load_offs + rels->r_offset); + newval = ooff + this->st_value; + + if (*r_addr != newval) + *r_addr = newval; + + return newval; +} + |