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No commits in common. "9a3ccc2fc13150af418d4fbee266fd593891ec45" and "0eec2bf24de9f6dd1af82afe0544539c0962958a" have entirely different histories.
9a3ccc2fc1
...
0eec2bf24d
5 changed files with 19 additions and 109 deletions
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@ -6,7 +6,6 @@
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#
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.extern main
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.globl _start
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.stack
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.align 2
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29
mld/link.c
29
mld/link.c
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@ -44,7 +44,7 @@ static int load_objects(struct linker *linker)
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// load obj file
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linker->obj_len++;
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if (object_load(obj, path, i+1))
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if (object_load(obj, path))
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return M_ERROR;
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skip_obj:
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}
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@ -55,7 +55,7 @@ skip_obj:
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char *path = _STR(PREFIX) "/lib/mips/runtime.o";
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struct object *obj = &linker->objects[linker->obj_len++];
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if (object_load(obj, path, 0))
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if (object_load(obj, path))
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return M_ERROR;
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#undef _STR
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@ -208,7 +208,7 @@ static int relocate_symbol(struct linker *linker, struct object *obj,
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new.st_shndx = B16(new_shndx);
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new.st_size = 0;
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if (symtab_get(&linker->symtab, NULL, name, obj->index) == M_SUCCESS) {
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if (symtab_get(&linker->symtab, NULL, name) == M_SUCCESS) {
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ERROR("cannot link doubly defiend symbol '%s'", name);
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return M_ERROR;
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}
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@ -216,9 +216,6 @@ static int relocate_symbol(struct linker *linker, struct object *obj,
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if (symtab_push(&linker->symtab, &new))
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return M_ERROR;
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if (symtab_map_push(&linker->symtab_map, obj))
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return M_ERROR;
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return M_SUCCESS;
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}
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@ -383,12 +380,12 @@ static int relocate_instruction_rela(struct linker *linker,
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/// of this relocation in that segment part
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uint32_t off = B32(rel->r_offset);
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if (off > seg->size) {
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ERROR("invalid relocation in '%s'", seg->obj->name);
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ERROR("relocation in segment '%s' out of bounds", seg->name);
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return M_ERROR;
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}
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if (B32(rel->r_info) == 0) {
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WARNING("skiping empty relocation entry in '%s'", seg->name);
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WARNING("skiping empty relocation entry");
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return M_SUCCESS;
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}
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@ -400,21 +397,22 @@ static int relocate_instruction_rela(struct linker *linker,
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/// read the symbol from the relocation
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struct symbol_table *symtab = seg->reltab.symtab;
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if (idx >= symtab->len) {
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ERROR("invalid relocation in '%s'", seg->obj->name);
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ERROR("relocation in segment '%s', symbol index [%d] out of "
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"bounds", seg->name, idx);
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return M_ERROR;
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}
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Elf32_Sym *sym = &symtab->syms[idx];
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char const *sym_name = symtab->strtab->data + B32(sym->st_name);
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if (B32(sym->st_name) >= symtab->strtab->len) {
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ERROR("symbol name out of bounds in '%s'", seg->obj->name);
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ERROR("relocation symbol name out of bounds");
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return M_ERROR;
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}
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// get the new sym for the new vaddr
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Elf32_Sym *new_sym = NULL;
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if (symtab_get(&linker->symtab, &new_sym, sym_name, seg->obj->index)) {
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ERROR("symbol '%s' undefined", sym_name);
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if (symtab_get(&linker->symtab, &new_sym, sym_name)) {
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ERROR("relocation symbol not found");
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return M_ERROR;
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}
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@ -658,7 +656,7 @@ static int link_executable(struct linker *linker)
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ehdr->e_shstrndx = B16(linker->shstrtab_shidx);
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Elf32_Sym *entry = NULL;
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if (symtab_get(&linker->symtab, &entry, "_start", -1)) {
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if (symtab_get(&linker->symtab, &entry, "_start")) {
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ERROR("undefined symbol _start");
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return M_ERROR;
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}
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@ -683,7 +681,6 @@ static int linker_init(struct linker *linker, struct linker_arguments *args)
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linker->objects = NULL;
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linker->segments.size = 0;
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linker->symtab.syms = NULL;
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linker->symtab_map.meta = NULL;
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linker->shstrtab.data = NULL;
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linker->strtab.data = NULL;
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linker->shdr = NULL;
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@ -696,10 +693,7 @@ static int linker_init(struct linker *linker, struct linker_arguments *args)
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return M_ERROR;
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if (symtab_init(&linker->symtab))
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return M_ERROR;
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if (symtab_map_init(&linker->symtab_map))
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return M_ERROR;
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linker->symtab.strtab = &linker->strtab;
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linker->symtab.map = &linker->symtab_map;
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return M_SUCCESS;
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}
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@ -718,7 +712,6 @@ static void linker_free(struct linker *linker)
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strtab_free(&linker->shstrtab);
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strtab_free(&linker->strtab);
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symtab_free(&linker->symtab);
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symtab_map_free(&linker->symtab_map);
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}
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int link_files(struct linker_arguments args) {
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30
mld/link.h
30
mld/link.h
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@ -39,9 +39,6 @@
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struct linker;
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struct object;
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struct segment;
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struct string_table;
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struct symbol_table;
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struct symbol_table_mapping;
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///
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/// relocation table
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@ -82,35 +79,13 @@ struct symbol_table {
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Elf32_Sym *syms;
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size_t len;
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size_t size;
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// mapping for global symbol table
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// can be null
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// (metadata for each symbol)
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struct symbol_table_mapping *map;
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};
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///
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/// symbol table map
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/// (metadata for each symbol)
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///
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int symtab_init(struct symbol_table *symtab);
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void symtab_free(struct symbol_table *symtab);
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int symtab_push(struct symbol_table *symtab, const Elf32_Sym *sym);
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int symtab_get(struct symbol_table *symtab, Elf32_Sym **sym, const char *name,
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int32_t obj_idx);
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struct symbol_table_mapping {
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uint32_t len;
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uint32_t size;
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struct object **meta;
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};
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int symtab_map_push(struct symbol_table_mapping *symtabm, struct object *seg);
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int symtab_map_init(struct symbol_table_mapping *symtabm);
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void symtab_map_free(struct symbol_table_mapping *symtabm);
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int symtab_get(struct symbol_table *symtab, Elf32_Sym **sym, const char *name);
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///
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/// segment
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@ -236,7 +211,7 @@ struct object {
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struct symbol_table *symtabs;
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};
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int object_load(struct object *object, char *path, uint32_t index);
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int object_load(struct object *object, char *path);
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void object_free(struct object *object);
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@ -260,7 +235,6 @@ struct linker {
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struct string_table shstrtab;
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struct string_table strtab;
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struct symbol_table symtab;
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struct symbol_table_mapping symtab_map;
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// output elf
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Elf32_Ehdr ehdr;
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@ -276,7 +276,7 @@ static int map_file(struct object *obj, char *path)
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return M_SUCCESS;
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}
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int object_load(struct object *object, char *path, uint32_t index)
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int object_load(struct object *object, char *path)
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{
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current_file = path;
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@ -286,7 +286,6 @@ int object_load(struct object *object, char *path, uint32_t index)
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object->strtabs = NULL;
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object->mapped = NULL;
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object->name = path;
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object->index = index;
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/** load the file */
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if (map_file(object, path))
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61
mld/symtab.c
61
mld/symtab.c
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@ -1,6 +1,5 @@
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#include <elf.h>
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#include <merror.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <melf.h>
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@ -20,7 +19,6 @@ int symtab_init(struct symbol_table *symtab)
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}
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symtab->syms[0] = (Elf32_Sym){0};
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symtab->map = NULL;
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return M_SUCCESS;
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}
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@ -47,69 +45,16 @@ int symtab_push(struct symbol_table *symtab, const Elf32_Sym *sym)
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return M_SUCCESS;
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}
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int symtab_get(struct symbol_table *symtab, Elf32_Sym **res, const char *name,
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int32_t obj_idx)
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int symtab_get(struct symbol_table *symtab, Elf32_Sym **res, const char *name)
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{
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for (size_t i = 0; i < symtab->len; i++) {
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Elf32_Sym *sym = &symtab->syms[i];
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const char *symname = symtab->strtab->data + B32(sym->st_name);
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if (strcmp(name, symname) != 0)
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continue;
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// only allow retrevial of local variables from the
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// same object
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if (sym->st_info >> 4 != STB_GLOBAL && symtab->map != NULL &&
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obj_idx >= 0) {
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struct object *obj = symtab->map->meta[i];
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if (obj->index != (uint32_t)obj_idx)
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continue;
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} else if (obj_idx < 0 && sym->st_info >> 4 != STB_GLOBAL) {
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// when obj_idx is -1, we only want to reutrn
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// global symbols
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continue;
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}
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if (strcmp(name, symname) == 0) {
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if (res != NULL)
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*res = sym;
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return M_SUCCESS;
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}
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}
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return M_ERROR;
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}
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int symtab_map_push(struct symbol_table_mapping *symtabm, struct object *meta)
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{
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if (symtabm->len >= symtabm->size) {
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uint32_t size = symtabm->size * 2;
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void *new = realloc(symtabm->meta,
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sizeof(struct object *) * size);
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if (new == NULL) {
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PERROR("cannot realloc");
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return M_ERROR;
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}
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symtabm->size = size;
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symtabm->meta = new;
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}
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symtabm->meta[symtabm->len++] = meta;
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return M_SUCCESS;
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}
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int symtab_map_init(struct symbol_table_mapping *symtabm)
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{
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symtabm->len = 0;
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symtabm->size = SYMTAB_INIT_LEN;
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symtabm->meta = malloc(sizeof(struct object *) * symtabm->size);
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if (symtabm->meta == NULL) {
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PERROR("cannot alloc");
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return M_ERROR;
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}
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return M_SUCCESS;
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}
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void symtab_map_free(struct symbol_table_mapping *symtabm)
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{
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free(symtabm->meta);
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}
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