diff options
Diffstat (limited to 'ldso/ldso/metag/elfinterp.c')
| -rw-r--r-- | ldso/ldso/metag/elfinterp.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/ldso/ldso/metag/elfinterp.c b/ldso/ldso/metag/elfinterp.c new file mode 100644 index 000000000..78434167b --- /dev/null +++ b/ldso/ldso/metag/elfinterp.c @@ -0,0 +1,299 @@ +/* + * Meta ELF shared library loader support. + * + * Program to load an elf binary on a linux system, and run it. + * References to symbols in sharable libraries can be resolved + * by either an ELF sharable library or a linux style of shared + * library. + * + * Copyright (C) 2013, Imagination Technologies Ltd. + * + * Licensed under LGPL v2.1 or later, see the file COPYING.LIB in this tarball. + */ + +#include "ldso.h" + +/* Defined in resolve.S. */ +extern int _dl_linux_resolve(void); + +static inline unsigned long __get_unaligned_reloc(unsigned long *addr) +{ + char *rel_addr = (char *)addr; + unsigned long val; + + val = *rel_addr++ & 0xff; + val |= (*rel_addr++ << 8) & 0x0000ff00; + val |= (*rel_addr++ << 16) & 0x00ff0000; + val |= (*rel_addr++ << 24) & 0xff000000; + + return val; +} + +static inline void __put_unaligned_reloc(unsigned long *addr, + unsigned long val) +{ + char *rel_addr = (char *)addr; + + *rel_addr++ = (val & 0x000000ff); + *rel_addr++ = ((val & 0x0000ff00) >> 8); + *rel_addr++ = ((val & 0x00ff0000) >> 16); + *rel_addr++ = ((val & 0xff000000) >> 24); +} + +unsigned long +_dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry) +{ + int reloc_type; + int symtab_index; + char *strtab; + char *symname; + char *new_addr; + char *rel_addr; + char **got_addr; + Elf32_Sym *symtab; + ELF_RELOC *this_reloc; + unsigned long instr_addr; + + rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL]; + + this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry); + reloc_type = ELF32_R_TYPE(this_reloc->r_info); + symtab_index = ELF32_R_SYM(this_reloc->r_info); + + symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB]; + strtab = (char *)tpnt->dynamic_info[DT_STRTAB]; + symname = strtab + symtab[symtab_index].st_name; + + if (unlikely(reloc_type != R_METAG_JMP_SLOT)) { + _dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n", + _dl_progname); + _dl_exit(1); + } + + /* Address of the jump instruction to fix up. */ + instr_addr = ((unsigned long)this_reloc->r_offset + + (unsigned long)tpnt->loadaddr); + got_addr = (char **)instr_addr; + + /* Get the address of the GOT entry. */ + new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, + ELF_RTYPE_CLASS_PLT, NULL); + if (unlikely(!new_addr)) { + _dl_dprintf(2, "%s: Can't resolve symbol '%s'\n", _dl_progname, symname); + _dl_exit(1); + } + +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_bindings) { + _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname); + if (_dl_debug_detail) + _dl_dprintf(_dl_debug_file, + "\n\tpatched: %x ==> %x @ %x\n", + *got_addr, new_addr, got_addr); + } + if (!_dl_debug_nofixups) { + *got_addr = new_addr; + } +#else + *got_addr = new_addr; +#endif + + return (unsigned long)new_addr; +} + +static int +_dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope, + unsigned long rel_addr, unsigned long rel_size, + int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope, + ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)) +{ + int symtab_index; + unsigned int i; + char *strtab; + Elf32_Sym *symtab; + ELF_RELOC *rpnt; + + /* Parse the relocation information. */ + rpnt = (ELF_RELOC *)(intptr_t)rel_addr; + rel_size /= sizeof(ELF_RELOC); + + symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB]; + strtab = (char *)tpnt->dynamic_info[DT_STRTAB]; + + for (i = 0; i < rel_size; i++, rpnt++) { + int res; + + symtab_index = ELF32_R_SYM(rpnt->r_info); + + debug_sym(symtab, strtab, symtab_index); + debug_reloc(symtab, strtab, rpnt); + + /* Pass over to actual relocation function. */ + res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab); + + if (res == 0) + continue; + + _dl_dprintf(2, "\n%s: ", _dl_progname); + + if (symtab_index) + _dl_dprintf(2, "symbol '%s': ", + strtab + symtab[symtab_index].st_name); + + if (unlikely(res < 0)) { + int reloc_type = ELF32_R_TYPE(rpnt->r_info); + +#if defined (__SUPPORT_LD_DEBUG__) + _dl_dprintf(2, "can't handle reloc type %s\n", + _dl_reltypes(reloc_type)); +#else + _dl_dprintf(2, "can't handle reloc type %x\n", + reloc_type); +#endif + _dl_exit(-res); + } else if (unlikely(res > 0)) { + _dl_dprintf(2, "can't resolve symbol\n"); + return res; + } + } + + return 0; +} + +static int +_dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope, + ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab) +{ + int reloc_type; + int symtab_index; + char *symname = NULL; + unsigned long *reloc_addr; + unsigned long symbol_addr; +#if defined (__SUPPORT_LD_DEBUG__) + unsigned long old_val; +#endif + + reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset); + reloc_type = ELF32_R_TYPE(rpnt->r_info); + symtab_index = ELF32_R_SYM(rpnt->r_info); + symbol_addr = 0; + symname = strtab + symtab[symtab_index].st_name; + + if (symtab_index) { + if (symtab[symtab_index].st_shndx != SHN_UNDEF && + ELF32_ST_BIND(symtab[symtab_index].st_info) == STB_LOCAL) { + symbol_addr = (unsigned long)tpnt->loadaddr; + } else { + symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt, + elf_machine_type_class(reloc_type), NULL); + } + + if (unlikely(!symbol_addr && ELF32_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) { + _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname); + _dl_exit(1); + }; + + symbol_addr += rpnt->r_addend; + } + +#if defined (__SUPPORT_LD_DEBUG__) + if (reloc_type != R_METAG_NONE) + old_val = __get_unaligned_reloc(reloc_addr); +#endif + + switch (reloc_type) { + case R_METAG_NONE: + break; + case R_METAG_GLOB_DAT: + case R_METAG_JMP_SLOT: + case R_METAG_ADDR32: + __put_unaligned_reloc(reloc_addr, symbol_addr); + break; + case R_METAG_COPY: +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_move) + _dl_dprintf(_dl_debug_file, + "\t%s move %d bytes from %x to %x\n", + symname, symtab[symtab_index].st_size, + symbol_addr, reloc_addr); +#endif + + _dl_memcpy((char *)reloc_addr, + (char *)symbol_addr, + symtab[symtab_index].st_size); + break; + case R_METAG_RELATIVE: + __put_unaligned_reloc(reloc_addr, + (unsigned long)tpnt->loadaddr + + rpnt->r_addend); + break; + default: + return -1; /* Calls _dl_exit(1). */ + } + +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_reloc && _dl_debug_detail && + (reloc_type != R_METAG_NONE)) { + unsigned long new_val = __get_unaligned_reloc(reloc_addr); + _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n", + old_val, new_val, reloc_addr); + } +#endif + + return 0; +} + +static int +_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope, + ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab) +{ + int reloc_type; + unsigned long *reloc_addr; +#if defined (__SUPPORT_LD_DEBUG__) + unsigned long old_val; +#endif + + reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset); + reloc_type = ELF32_R_TYPE(rpnt->r_info); + +#if defined (__SUPPORT_LD_DEBUG__) + old_val = *reloc_addr; +#endif + + switch (reloc_type) { + case R_METAG_NONE: + break; + case R_METAG_JMP_SLOT: + *reloc_addr += (unsigned long)tpnt->loadaddr; + break; + default: + return -1; /* Calls _dl_exit(1). */ + } + +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_reloc && _dl_debug_detail) + _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n", + old_val, *reloc_addr, reloc_addr); +#endif + + return 0; +} + +/* External interface to the generic part of the dynamic linker. */ + +void +_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt, + unsigned long rel_addr, + unsigned long rel_size) +{ + _dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc); +} + +int +_dl_parse_relocation_information(struct dyn_elf *rpnt, + unsigned long rel_addr, + unsigned long rel_size) +{ + return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, + rel_size, _dl_do_reloc); +} |