399 lines
9.4 KiB
C
399 lines
9.4 KiB
C
/* $NetBSD: mdreloc.c,v 1.23 2003/07/26 15:04:38 mrg Exp $ */
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD: src/libexec/rtld-elf/arm/reloc.c,v 1.4.8.1 2009/04/15 03:14:26 kensmith Exp $");
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#include <sys/param.h>
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#include <sys/mman.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "debug.h"
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#include "rtld.h"
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void
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init_pltgot(Obj_Entry *obj)
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{
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if (obj->pltgot != NULL) {
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obj->pltgot[1] = (Elf_Addr) obj;
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obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
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}
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}
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int
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do_copy_relocations(Obj_Entry *dstobj)
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{
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const Elf_Rel *rellim;
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const Elf_Rel *rel;
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assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */
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rellim = (const Elf_Rel *) ((caddr_t) dstobj->rel + dstobj->relsize);
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for (rel = dstobj->rel; rel < rellim; rel++) {
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if (ELF_R_TYPE(rel->r_info) == R_ARM_COPY) {
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void *dstaddr;
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const Elf_Sym *dstsym;
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const char *name;
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unsigned long hash;
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size_t size;
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const void *srcaddr;
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const Elf_Sym *srcsym;
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Obj_Entry *srcobj;
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const Ver_Entry *ve;
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dstaddr = (void *) (dstobj->relocbase + rel->r_offset);
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dstsym = dstobj->symtab + ELF_R_SYM(rel->r_info);
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name = dstobj->strtab + dstsym->st_name;
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hash = elf_hash(name);
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size = dstsym->st_size;
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ve = fetch_ventry(dstobj, ELF_R_SYM(rel->r_info));
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for (srcobj = dstobj->next; srcobj != NULL; srcobj = srcobj->next)
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if ((srcsym = symlook_obj(name, hash, srcobj, ve, 0)) != NULL)
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break;
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if (srcobj == NULL) {
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_rtld_error("Undefined symbol \"%s\" referenced from COPY"
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" relocation in %s", name, dstobj->path);
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return -1;
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}
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srcaddr = (const void *) (srcobj->relocbase + srcsym->st_value);
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memcpy(dstaddr, srcaddr, size);
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}
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}
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return 0;
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}
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void _rtld_bind_start(void);
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void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
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int open();
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int _open();
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void
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_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
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{
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const Elf_Rel *rel = 0, *rellim;
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Elf_Addr relsz = 0;
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Elf_Addr *where;
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for (; dynp->d_tag != DT_NULL; dynp++) {
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switch (dynp->d_tag) {
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case DT_REL:
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rel = (const Elf_Rel *)(relocbase + dynp->d_un.d_ptr);
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break;
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case DT_RELSZ:
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relsz = dynp->d_un.d_val;
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break;
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}
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}
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rellim = (const Elf_Rel *)((caddr_t)rel + relsz);
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for (; rel < rellim; rel++) {
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where = (Elf_Addr *)(relocbase + rel->r_offset);
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*where += (Elf_Addr)relocbase;
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}
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}
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/*
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* It is possible for the compiler to emit relocations for unaligned data.
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* We handle this situation with these inlines.
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*/
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#define RELOC_ALIGNED_P(x) \
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(((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
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static __inline Elf_Addr
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load_ptr(void *where)
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{
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Elf_Addr res;
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memcpy(&res, where, sizeof(res));
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return (res);
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}
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static __inline void
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store_ptr(void *where, Elf_Addr val)
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{
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memcpy(where, &val, sizeof(val));
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}
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static int
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reloc_nonplt_object(Obj_Entry *obj, const Elf_Rel *rel, SymCache *cache)
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{
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Elf_Addr *where;
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const Elf_Sym *def;
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const Obj_Entry *defobj;
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Elf_Addr tmp;
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unsigned long symnum;
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where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
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symnum = ELF_R_SYM(rel->r_info);
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/*
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* cbass:
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* This is the second relocation run for LDSO, relocate global
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* symbols only, in order to resolve e.g. type informations in
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* binary
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*/
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if (obj->rtld && !(obj->rtld_init)) {
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switch (ELF_R_TYPE(rel->r_info)) {
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case R_ARM_GLOB_DAT: /* word32 B + S */
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def = find_symdef(symnum, obj, &defobj, false, cache);
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if (def == NULL || defobj==NULL)
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return 0;
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*where = (Elf_Addr)defobj->relocbase +
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def->st_value;
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default:
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return 0;
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}
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}
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switch (ELF_R_TYPE(rel->r_info)) {
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case R_ARM_NONE:
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/* XXX cbass: Ignore TLS relocations */
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case R_ARM_TLS_DTPMOD32:
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break;
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#if 1 /* XXX should not occur */
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case R_ARM_PC24: { /* word32 S - P + A */
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Elf32_Sword addend;
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/*
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* Extract addend and sign-extend if needed.
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*/
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addend = *where;
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if (addend & 0x00800000)
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addend |= 0xff000000;
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def = find_symdef(symnum, obj, &defobj, false, cache);
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if (def == NULL)
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return -1;
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tmp = (Elf_Addr)obj->relocbase + def->st_value
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- (Elf_Addr)where + (addend << 2);
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if ((tmp & 0xfe000000) != 0xfe000000 &&
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(tmp & 0xfe000000) != 0) {
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_rtld_error(
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"%s: R_ARM_PC24 relocation @ %p to %s failed "
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"(displacement %ld (%#lx) out of range)",
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obj->path, where,
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obj->strtab + obj->symtab[symnum].st_name,
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(long) tmp, (long) tmp);
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return -1;
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}
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tmp >>= 2;
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*where = (*where & 0xff000000) | (tmp & 0x00ffffff);
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dbg("PC24 %s in %s --> %p @ %p in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)*where, where, defobj->path);
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break;
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}
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#endif
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case R_ARM_REL32: /* word32 S - P + A */
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def = find_symdef(symnum, obj, &defobj, false, cache);
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if (def == NULL)
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return -1;
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*where = (Elf_Addr)defobj->relocbase + def->st_value - (Elf_Addr)where
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+ *where;
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break;
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case R_ARM_ABS32: /* word32 B + S + A */
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case R_ARM_GLOB_DAT: /* word32 B + S */
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def = find_symdef(symnum, obj, &defobj, false, cache);
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/* cbass: Skip undefined symbols */
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if (def == NULL || defobj==NULL)
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return 0;
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if (__predict_true(RELOC_ALIGNED_P(where))) {
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tmp = *where + (Elf_Addr)defobj->relocbase +
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def->st_value;
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*where = tmp;
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} else {
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tmp = load_ptr(where) +
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(Elf_Addr)defobj->relocbase +
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def->st_value;
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store_ptr(where, tmp);
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}
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dbg("ABS32/GLOB_DAT %s in %s --> %p @ %p in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)tmp, where, defobj->path);
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break;
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case R_ARM_RELATIVE: /* word32 B + A */
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if (__predict_true(RELOC_ALIGNED_P(where))) {
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tmp = *where + (Elf_Addr)obj->relocbase;
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if (obj->relocbase)
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*where = tmp;
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} else {
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tmp = load_ptr(where) +
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(Elf_Addr)obj->relocbase;
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store_ptr(where, tmp);
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}
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dbg("RELATIVE in %s --> %p", obj->path,
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(void *)tmp);
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break;
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case R_ARM_COPY:
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/*
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* These are deferred until all other relocations have
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* been done. All we do here is make sure that the
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* COPY relocation is not in a shared library. They
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* are allowed only in executable files.
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*/
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if (!obj->mainprog) {
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_rtld_error(
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"%s: Unexpected R_COPY relocation in shared library",
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obj->path);
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return -1;
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}
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dbg("COPY (avoid in main)");
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break;
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default:
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dbg("sym = %lu, type = %lu, offset = %p, "
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"contents = %p, symbol = %s",
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symnum, (u_long)ELF_R_TYPE(rel->r_info),
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(void *)rel->r_offset, (void *)load_ptr(where),
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obj->strtab + obj->symtab[symnum].st_name);
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_rtld_error("%s: Unsupported relocation type %ld "
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"in non-PLT relocations\n",
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obj->path, (u_long) ELF_R_TYPE(rel->r_info));
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return -1;
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}
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return 0;
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}
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/*
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* * Process non-PLT relocations
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* */
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int
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reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
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{
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const Elf_Rel *rellim;
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const Elf_Rel *rel;
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SymCache *cache;
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int bytes = obj->nchains * sizeof(SymCache);
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int r = -1;
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/*
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* The dynamic loader may be called from a thread, we have
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* limited amounts of stack available so we cannot use alloca().
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*/
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int flags = obj->rtld_init ? MAP_LDSO : 0;
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cache = mmap(NULL, bytes, PROT_READ|PROT_WRITE, MAP_ANON|flags, -1, 0);
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if (cache == MAP_FAILED)
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cache = NULL;
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rellim = (const Elf_Rel *)((caddr_t)obj->rel + obj->relsize);
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for (rel = obj->rel; rel < rellim; rel++) {
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if (reloc_nonplt_object(obj, rel, cache) < 0)
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goto done;
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}
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r = 0;
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done:
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/*
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* Do not unmap if LDSO is in initialization, since some ctors might not
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* be called, yet.
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*/
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if (cache && !(obj->rtld_init)) {
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munmap(cache, bytes);
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}
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return (r);
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}
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/*
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* * Process the PLT relocations.
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* */
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int
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reloc_plt(Obj_Entry *obj)
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{
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const Elf_Rel *rellim;
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const Elf_Rel *rel;
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rellim = (const Elf_Rel *)((char *)obj->pltrel +
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obj->pltrelsize);
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for (rel = obj->pltrel; rel < rellim; rel++) {
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Elf_Addr *where;
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assert(ELF_R_TYPE(rel->r_info) == R_ARM_JUMP_SLOT);
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where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
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*where += (Elf_Addr )obj->relocbase;
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}
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return (0);
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}
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/*
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* * LD_BIND_NOW was set - force relocation for all jump slots
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* */
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int
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reloc_jmpslots(Obj_Entry *obj)
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{
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const Obj_Entry *defobj;
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const Elf_Rel *rellim;
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const Elf_Rel *rel;
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const Elf_Sym *def;
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Elf_Addr *where;
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Elf_Addr target;
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rellim = (const Elf_Rel *)((char *)obj->pltrel + obj->pltrelsize);
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for (rel = obj->pltrel; rel < rellim; rel++) {
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assert(ELF_R_TYPE(rel->r_info) == R_ARM_JUMP_SLOT);
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where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
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def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
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true, NULL);
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if (def == NULL) {
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dbg("reloc_jmpslots: sym not found");
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return (-1);
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}
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/* skip undefined symbols in linker */
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if (defobj == NULL && obj->rtld)
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continue;
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target = (Elf_Addr)(defobj->relocbase + def->st_value);
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reloc_jmpslot(where, target, defobj, obj,
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(const Elf_Rel *) rel);
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}
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obj->jmpslots_done = true;
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return (0);
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}
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Elf_Addr
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reloc_jmpslot(Elf_Addr *where, Elf_Addr target, const Obj_Entry *defobj,
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const Obj_Entry *obj, const Elf_Rel *rel)
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{
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assert(ELF_R_TYPE(rel->r_info) == R_ARM_JUMP_SLOT);
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if (*where != target)
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*where = target;
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return target;
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}
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void
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allocate_initial_tls(Obj_Entry *objs)
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{
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}
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void *
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__tls_get_addr(tls_index* ti)
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{
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/* XXX cbass: We don't support tls, but some compilers use TLS. Just for the
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* sake of it: Provide some memory ... and best wishes!
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*/
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static char _tls[64];
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return _tls;
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}
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