diff options
Diffstat (limited to 'cpukit/libdl/rtl-elf.c')
| -rw-r--r-- | cpukit/libdl/rtl-elf.c | 346 |
1 files changed, 256 insertions, 90 deletions
diff --git a/cpukit/libdl/rtl-elf.c b/cpukit/libdl/rtl-elf.c index c1821bcfda..762130b9e7 100644 --- a/cpukit/libdl/rtl-elf.c +++ b/cpukit/libdl/rtl-elf.c @@ -64,31 +64,40 @@ rtems_rtl_elf_machine_check (Elf_Ehdr* ehdr) return true; } -bool -rtems_rtl_elf_find_symbol (rtems_rtl_obj* obj, - const Elf_Sym* sym, - const char* symname, - Elf_Word* value) +static bool +rtems_rtl_elf_find_symbol (rtems_rtl_obj* obj, + const Elf_Sym* sym, + const char* symname, + rtems_rtl_obj_sym** symbol, + Elf_Word* value) { rtems_rtl_obj_sect* sect; - if (ELF_ST_TYPE(sym->st_info) == STT_NOTYPE || - sym->st_shndx == SHN_COMMON) + /* + * If the symbol type is STT_NOTYPE the symbol references a global + * symbol. The gobal symbol table is searched to find it and that value + * returned. If the symbol is local to the object module the section for the + * symbol is located and it's base added to the symbol's value giving an + * absolute location. + */ + if (ELF_ST_TYPE(sym->st_info) == STT_NOTYPE || sym->st_shndx == SHN_COMMON) { /* * Search the object file then the global table for the symbol. */ - rtems_rtl_obj_sym* symbol = rtems_rtl_symbol_obj_find (obj, symname); - if (!symbol) + *symbol = rtems_rtl_symbol_obj_find (obj, symname); + if (!*symbol) { rtems_rtl_set_error (EINVAL, "global symbol not found: %s", symname); return false; } - *value = (Elf_Addr) symbol->value; + *value = (Elf_Addr) (*symbol)->value; return true; } + *symbol = NULL; + sect = rtems_rtl_obj_find_section_by_index (obj, sym->st_shndx); if (!sect) { @@ -100,11 +109,161 @@ rtems_rtl_elf_find_symbol (rtems_rtl_obj* obj, return true; } +/** + * Relocation worker routine. + */ +typedef bool (*rtems_rtl_elf_reloc_handler)(rtems_rtl_obj* obj, + bool is_rela, + void* relbuf, + rtems_rtl_obj_sect* targetsect, + rtems_rtl_obj_sym* symbol, + Elf_Sym* sym, + const char* symname, + Elf_Word symvalue, + bool resolved, + void* data); + +/** + * Relocation parser data. + */ +typedef struct +{ + size_t dependents; /**< The number of dependent object files. */ + size_t unresolved; /**< The number of unresolved symbols. */ +} rtems_rtl_elf_reloc_data; + +static bool +rtems_rtl_elf_reloc_parser (rtems_rtl_obj* obj, + bool is_rela, + void* relbuf, + rtems_rtl_obj_sect* targetsect, + rtems_rtl_obj_sym* symbol, + Elf_Sym* sym, + const char* symname, + Elf_Word symvalue, + bool resolved, + void* data) +{ + rtems_rtl_elf_reloc_data* rd = (rtems_rtl_elf_reloc_data*) data; + /* + * If the symbol has been resolved and there is a symbol name it is a global + * symbol and from another object file so add it as a dependency. + */ + if (!resolved) + { + ++rd->unresolved; + } + else if (resolved && symname != NULL) + { + /* + * Find the symbol's object file. It cannot be NULL so ignore that result + * if returned, it means something is corrupted. We are in an iterator. + */ + rtems_rtl_obj* sobj = rtems_rtl_find_obj_with_symbol (symbol); + if (sobj != NULL) + { + /* + * A dependency is not the base kernel image or itself. Tag the object as + * having been visited so we count it only once. + */ + if (sobj != rtems_rtl_baseimage () && obj != sobj && + (sobj->flags & RTEMS_RTL_OBJ_RELOC_TAG) == 0) + { + sobj->flags |= RTEMS_RTL_OBJ_RELOC_TAG; + ++rd->dependents; + } + } + } + return true; +} + +static bool +rtems_rtl_elf_reloc_relocator (rtems_rtl_obj* obj, + bool is_rela, + void* relbuf, + rtems_rtl_obj_sect* targetsect, + rtems_rtl_obj_sym* symbol, + Elf_Sym* sym, + const char* symname, + Elf_Word symvalue, + bool resolved, + void* data) +{ + const Elf_Rela* rela = (const Elf_Rela*) relbuf; + const Elf_Rel* rel = (const Elf_Rel*) relbuf; + + if (!resolved) + { + uint16_t flags = 0; + rtems_rtl_word rel_words[3]; + + if (is_rela) + { + flags = 1; + rel_words[REL_R_OFFSET] = rela->r_offset; + rel_words[REL_R_INFO] = rela->r_info; + rel_words[REL_R_ADDEND] = rela->r_addend; + } + else + { + rel_words[REL_R_OFFSET] = rel->r_offset; + rel_words[REL_R_INFO] = rel->r_info; + rel_words[REL_R_ADDEND] = 0; + } + + if (!rtems_rtl_unresolved_add (obj, + flags, + symname, + targetsect->section, + rel_words)) + return false; + + ++obj->unresolved; + } + else + { + rtems_rtl_obj* sobj; + + if (is_rela) + { + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) + printf ("rtl: rela: sym:%s(%d)=%08jx type:%d off:%08jx addend:%d\n", + symname, (int) ELF_R_SYM (rela->r_info), + (uintmax_t) symvalue, (int) ELF_R_TYPE (rela->r_info), + (uintmax_t) rela->r_offset, (int) rela->r_addend); + if (!rtems_rtl_elf_relocate_rela (obj, rela, targetsect, + symname, sym->st_info, symvalue)) + return false; + } + else + { + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) + printf ("rtl: rel: sym:%s(%d)=%08jx type:%d off:%08jx\n", + symname, (int) ELF_R_SYM (rel->r_info), + (uintmax_t) symvalue, (int) ELF_R_TYPE (rel->r_info), + (uintmax_t) rel->r_offset); + if (!rtems_rtl_elf_relocate_rel (obj, rel, targetsect, + symname, sym->st_info, symvalue)) + return false; + } + + sobj = rtems_rtl_find_obj_with_symbol (symbol); + if (sobj != NULL) + { + if (rtems_rtl_obj_add_dependent (obj, sobj)) + rtems_rtl_obj_inc_reference (sobj); + } + } + + return true; +} + static bool -rtems_rtl_elf_relocator (rtems_rtl_obj* obj, - int fd, - rtems_rtl_obj_sect* sect, - void* data) +rtems_rtl_elf_relocate_worker (rtems_rtl_obj* obj, + int fd, + rtems_rtl_obj_sect* sect, + rtems_rtl_elf_reloc_handler handler, + void* data) { rtems_rtl_obj_cache* symbols; rtems_rtl_obj_cache* strings; @@ -155,15 +314,16 @@ rtems_rtl_elf_relocator (rtems_rtl_obj* obj, for (reloc = 0; reloc < (sect->size / reloc_size); ++reloc) { - uint8_t relbuf[reloc_size]; - const Elf_Rela* rela = (const Elf_Rela*) relbuf; - const Elf_Rel* rel = (const Elf_Rel*) relbuf; - Elf_Sym sym; - const char* symname = NULL; - off_t off; - Elf_Word type; - Elf_Word symvalue = 0; - bool relocate; + uint8_t relbuf[reloc_size]; + const Elf_Rela* rela = (const Elf_Rela*) relbuf; + const Elf_Rel* rel = (const Elf_Rel*) relbuf; + rtems_rtl_obj_sym* symbol = NULL; + Elf_Sym sym; + const char* symname = NULL; + off_t off; + Elf_Word rel_type; + Elf_Word symvalue = 0; + bool resolved; off = obj->ooffset + sect->offset + (reloc * reloc_size); @@ -203,75 +363,26 @@ rtems_rtl_elf_relocator (rtems_rtl_obj* obj, /* * See if the record references an external symbol. If it does find the * symbol value. If the symbol cannot be found flag the object file as - * having unresolved externals and store the externals. The load of an + * having unresolved externals and store the external. The load of an * object after this one may provide the unresolved externals. */ if (is_rela) - type = ELF_R_TYPE(rela->r_info); + rel_type = ELF_R_TYPE(rela->r_info); else - type = ELF_R_TYPE(rel->r_info); - - relocate = true; - - if (rtems_rtl_elf_rel_resolve_sym (type)) - { - if (!rtems_rtl_elf_find_symbol (obj, &sym, symname, &symvalue)) - { - uint16_t flags = 0; - rtems_rtl_word rel_words[3]; - - relocate = false; - - if (is_rela) - { - flags = 1; - rel_words[REL_R_OFFSET] = rela->r_offset; - rel_words[REL_R_INFO] = rela->r_info; - rel_words[REL_R_ADDEND] = rela->r_addend; - } - else - { - rel_words[REL_R_OFFSET] = rel->r_offset; - rel_words[REL_R_INFO] = rel->r_info; - rel_words[REL_R_ADDEND] = 0; - } + rel_type = ELF_R_TYPE(rel->r_info); - if (!rtems_rtl_unresolved_add (obj, - flags, - symname, - targetsect->section, - rel_words)) - return false; + resolved = true; - ++obj->unresolved; - } - } + if (rtems_rtl_elf_rel_resolve_sym (rel_type)) + resolved = rtems_rtl_elf_find_symbol (obj, + &sym, symname, + &symbol, &symvalue); - if (relocate) - { - if (is_rela) - { - if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) - printf ("rtl: rela: sym:%s(%d)=%08jx type:%d off:%08jx addend:%d\n", - symname, (int) ELF_R_SYM (rela->r_info), - (uintmax_t) symvalue, (int) ELF_R_TYPE (rela->r_info), - (uintmax_t) rela->r_offset, (int) rela->r_addend); - if (!rtems_rtl_elf_relocate_rela (obj, rela, targetsect, - symname, sym.st_info, symvalue)) - return false; - } - else - { - if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) - printf ("rtl: rel: sym:%s(%d)=%08jx type:%d off:%08jx\n", - symname, (int) ELF_R_SYM (rel->r_info), - (uintmax_t) symvalue, (int) ELF_R_TYPE (rel->r_info), - (uintmax_t) rel->r_offset); - if (!rtems_rtl_elf_relocate_rel (obj, rel, targetsect, - symname, sym.st_info, symvalue)) - return false; - } - } + if (!handler (obj, + is_rela, relbuf, targetsect, + symbol, &sym, symname, symvalue, resolved, + data)) + return false; } /* @@ -283,6 +394,28 @@ rtems_rtl_elf_relocator (rtems_rtl_obj* obj, return true; } +static bool +rtems_rtl_elf_relocs_parser (rtems_rtl_obj* obj, + int fd, + rtems_rtl_obj_sect* sect, + void* data) +{ + bool r = rtems_rtl_elf_relocate_worker (obj, fd, sect, + rtems_rtl_elf_reloc_parser, data); + rtems_rtl_obj_update_flags (RTEMS_RTL_OBJ_RELOC_TAG, 0); + return r; +} + +static bool +rtems_rtl_elf_relocs_locator (rtems_rtl_obj* obj, + int fd, + rtems_rtl_obj_sect* sect, + void* data) +{ + return rtems_rtl_elf_relocate_worker (obj, fd, sect, + rtems_rtl_elf_reloc_relocator, data); +} + bool rtems_rtl_obj_relocate_unresolved (rtems_rtl_unresolv_reloc* reloc, rtems_rtl_obj_sym* sym) @@ -290,8 +423,9 @@ rtems_rtl_obj_relocate_unresolved (rtems_rtl_unresolv_reloc* reloc, rtems_rtl_obj_sect* sect; bool is_rela; Elf_Word symvalue; + rtems_rtl_obj* sobj; - is_rela =reloc->flags & 1; + is_rela = reloc->flags & 1; sect = rtems_rtl_obj_find_section_by_index (reloc->obj, reloc->sect); if (!sect) @@ -329,13 +463,20 @@ rtems_rtl_obj_relocate_unresolved (rtems_rtl_unresolv_reloc* reloc, return false; } - if (reloc->obj->unresolved) + if (reloc->obj->unresolved > 0) { --reloc->obj->unresolved; - if (!reloc->obj->unresolved) + if (reloc->obj->unresolved == 0) reloc->obj->flags &= ~RTEMS_RTL_OBJ_UNRESOLVED; } + sobj = rtems_rtl_find_obj_with_symbol (sym); + if (sobj != NULL) + { + if (rtems_rtl_obj_add_dependent (reloc->obj, sobj)) + rtems_rtl_obj_inc_reference (sobj); + } + return true; } @@ -402,6 +543,24 @@ rtems_rtl_elf_common (rtems_rtl_obj* obj, } static bool +rtems_rtl_elf_dependents (rtems_rtl_obj* obj, rtems_rtl_elf_reloc_data* reloc) +{ + /* + * If there are dependencies and no unresolved externals allocate and size + * the dependency table to the number of dependent object files. If there are + * unresolved externals the number of dependencies is unknown at this point + * in time so use dynamic allocation to allocate the block size number of + * entries when the entries are added. + */ + if (reloc->dependents > 0 && reloc->unresolved == 0) + { + if (!rtems_rtl_obj_alloc_dependents (obj, reloc->dependents)) + return false; + } + return true; +} + +static bool rtems_rtl_elf_symbols (rtems_rtl_obj* obj, int fd, rtems_rtl_obj_sect* sect, @@ -1024,7 +1183,8 @@ rtems_rtl_elf_file_load (rtems_rtl_obj* obj, int fd) { rtems_rtl_obj_cache* header; Elf_Ehdr ehdr; - rtems_rtl_elf_common_data common = { .size = 0, .alignment = 0 }; + rtems_rtl_elf_reloc_data relocs = { 0 }; + rtems_rtl_elf_common_data common = { 0 }; rtems_rtl_obj_caches (&header, NULL, NULL); @@ -1102,10 +1262,16 @@ rtems_rtl_elf_file_load (rtems_rtl_obj* obj, int fd) if (!rtems_rtl_obj_load_sections (obj, fd, rtems_rtl_elf_loader, &ehdr)) return false; + if (!rtems_rtl_obj_relocate (obj, fd, rtems_rtl_elf_relocs_parser, &relocs)) + return false; + + if (!rtems_rtl_elf_dependents (obj, &relocs)) + return false; + if (!rtems_rtl_obj_load_symbols (obj, fd, rtems_rtl_elf_symbols, &ehdr)) return false; - if (!rtems_rtl_obj_relocate (obj, fd, rtems_rtl_elf_relocator, &ehdr)) + if (!rtems_rtl_obj_relocate (obj, fd, rtems_rtl_elf_relocs_locator, &ehdr)) return false; rtems_rtl_obj_synchronize_cache (obj); |