lib/runtime.asm

@@ -6,7 +6,6 @@
 #
 
 .extern main
-.globl _start
 
 .stack
 .align 2

mld/link.c

@@ -44,7 +44,7 @@ static int load_objects(struct linker *linker)
 
 		// load obj file
 		linker->obj_len++;
-		if (object_load(obj, path, i+1))
+		if (object_load(obj, path))
 			return M_ERROR;
 skip_obj:
 	}
@@ -55,7 +55,7 @@ skip_obj:
 
 		char *path = _STR(PREFIX) "/lib/mips/runtime.o";
 		struct object *obj = &linker->objects[linker->obj_len++];
-		if (object_load(obj, path, 0))
+		if (object_load(obj, path))
 			return M_ERROR;
 
 		#undef _STR
@@ -208,7 +208,7 @@ static int relocate_symbol(struct linker *linker, struct object *obj,
 	new.st_shndx = B16(new_shndx);
 	new.st_size = 0;
 
-	if (symtab_get(&linker->symtab, NULL, name, obj->index) == M_SUCCESS) {
+	if (symtab_get(&linker->symtab, NULL, name) == M_SUCCESS) {
 		ERROR("cannot link doubly defiend symbol '%s'", name);
 		return M_ERROR;
 	}
@@ -216,9 +216,6 @@ static int relocate_symbol(struct linker *linker, struct object *obj,
 	if (symtab_push(&linker->symtab, &new))
 		return M_ERROR;
 
-	if (symtab_map_push(&linker->symtab_map, obj))
-		return M_ERROR;
-
 	return M_SUCCESS;
 }
 
@@ -383,12 +380,12 @@ static int relocate_instruction_rela(struct linker *linker,
 	/// of this relocation in that segment part
 	uint32_t off = B32(rel->r_offset);
 	if (off > seg->size) {
-		ERROR("invalid relocation in '%s'", seg->obj->name);
+		ERROR("relocation in segment '%s' out of bounds", seg->name);
 		return M_ERROR;
 	}
 
 	if (B32(rel->r_info) == 0) {
-		WARNING("skiping empty relocation entry in '%s'", seg->name);
+		WARNING("skiping empty relocation entry");
 		return M_SUCCESS;
 	}
 
@@ -400,21 +397,22 @@ static int relocate_instruction_rela(struct linker *linker,
 	/// read the symbol from the relocation
 	struct symbol_table *symtab = seg->reltab.symtab;
 	if (idx >= symtab->len) {
-		ERROR("invalid relocation in '%s'", seg->obj->name);
+		ERROR("relocation in segment '%s', symbol index [%d] out of "
+			"bounds", seg->name, idx);
 		return M_ERROR;
 	}
 	Elf32_Sym *sym = &symtab->syms[idx];
 
 	char const *sym_name = symtab->strtab->data + B32(sym->st_name);
 	if (B32(sym->st_name) >= symtab->strtab->len) {
-		ERROR("symbol name out of bounds in '%s'", seg->obj->name);
+		ERROR("relocation symbol name out of bounds");
 		return M_ERROR;
 	}
 
 	// get the new sym for the new vaddr
 	Elf32_Sym *new_sym = NULL;
-	if (symtab_get(&linker->symtab, &new_sym, sym_name, seg->obj->index)) {
+	if (symtab_get(&linker->symtab, &new_sym, sym_name)) {
-		ERROR("symbol '%s' undefined", sym_name);
+		ERROR("relocation symbol not found");
 		return M_ERROR;
 	}
 
@@ -658,7 +656,7 @@ static int link_executable(struct linker *linker)
 	ehdr->e_shstrndx = B16(linker->shstrtab_shidx);
 
 	Elf32_Sym *entry = NULL;
-	if (symtab_get(&linker->symtab, &entry, "_start", -1)) {
+	if (symtab_get(&linker->symtab, &entry, "_start")) {
 		ERROR("undefined symbol _start");
 		return M_ERROR;
 	}
@@ -683,7 +681,6 @@ static int linker_init(struct linker *linker, struct linker_arguments *args)
 	linker->objects = NULL;
 	linker->segments.size = 0;
 	linker->symtab.syms = NULL;
-	linker->symtab_map.meta = NULL;
 	linker->shstrtab.data = NULL;
 	linker->strtab.data = NULL;
 	linker->shdr = NULL;
@@ -696,10 +693,7 @@ static int linker_init(struct linker *linker, struct linker_arguments *args)
 		return M_ERROR;
 	if (symtab_init(&linker->symtab))
 		return M_ERROR;
-	if (symtab_map_init(&linker->symtab_map))
-		return M_ERROR;
 	linker->symtab.strtab = &linker->strtab;
-	linker->symtab.map = &linker->symtab_map;
 	return M_SUCCESS;
 }
 
@@ -718,7 +712,6 @@ static void linker_free(struct linker *linker)
 	strtab_free(&linker->shstrtab);
 	strtab_free(&linker->strtab);
 	symtab_free(&linker->symtab);
-	symtab_map_free(&linker->symtab_map);
 }
 
 int link_files(struct linker_arguments args) {

mld/link.h

@@ -39,9 +39,6 @@
 struct linker;
 struct object;
 struct segment;
-struct string_table;
-struct symbol_table;
-struct symbol_table_mapping;
 
 ///
 /// relocation table
@@ -82,35 +79,13 @@ struct symbol_table {
 	Elf32_Sym *syms;
 	size_t len;
 	size_t size;
-
-	// mapping for global symbol table
-	// can be null
-	// (metadata for each symbol)
-	struct symbol_table_mapping *map;
 };
 
-///
-/// symbol table map
-/// (metadata for each symbol)
-///
-
 int symtab_init(struct symbol_table *symtab);
 void symtab_free(struct symbol_table *symtab);
 
 int symtab_push(struct symbol_table *symtab, const Elf32_Sym *sym);
-int symtab_get(struct symbol_table *symtab, Elf32_Sym **sym, const char *name,
+int symtab_get(struct symbol_table *symtab, Elf32_Sym **sym, const char *name);
-	       int32_t obj_idx);
-
-struct symbol_table_mapping {
-	uint32_t len;
-	uint32_t size;
-	struct object **meta;
-};
-
-int symtab_map_push(struct symbol_table_mapping *symtabm, struct object *seg);
-
-int symtab_map_init(struct symbol_table_mapping *symtabm);
-void symtab_map_free(struct symbol_table_mapping *symtabm);
 
 ///
 /// segment
@@ -236,7 +211,7 @@ struct object {
 	struct symbol_table *symtabs;
 };
 
-int object_load(struct object *object, char *path, uint32_t index);
+int object_load(struct object *object, char *path);
 
 void object_free(struct object *object);
 
@@ -260,7 +235,6 @@ struct linker {
 	struct string_table shstrtab;
 	struct string_table strtab;
 	struct symbol_table symtab;
-	struct symbol_table_mapping symtab_map;
 
 	// output elf
 	Elf32_Ehdr ehdr;

mld/obj.c

@@ -276,7 +276,7 @@ static int map_file(struct object *obj, char *path)
 	return M_SUCCESS;
 }
 
-int object_load(struct object *object, char *path, uint32_t index)
+int object_load(struct object *object, char *path)
 {
 	current_file = path;
 
@@ -286,7 +286,6 @@ int object_load(struct object *object, char *path, uint32_t index)
 	object->strtabs = NULL;
 	object->mapped = NULL;
 	object->name = path;
-	object->index = index;
 
 	/** load the file */
 	if (map_file(object, path))

mld/symtab.c

@@ -1,6 +1,5 @@
 #include <elf.h>
 #include <merror.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <melf.h>
 
@@ -20,7 +19,6 @@ int symtab_init(struct symbol_table *symtab)
 	}
 
 	symtab->syms[0] = (Elf32_Sym){0};
-	symtab->map = NULL;
 
 	return M_SUCCESS;
 }
@@ -47,69 +45,16 @@ int symtab_push(struct symbol_table *symtab, const Elf32_Sym *sym)
 	return M_SUCCESS;
 }
 
-int symtab_get(struct symbol_table *symtab, Elf32_Sym **res, const char *name,
+int symtab_get(struct symbol_table *symtab, Elf32_Sym **res, const char *name)
-	       int32_t obj_idx)
 {
 	for (size_t i = 0; i < symtab->len; i++) {
 		Elf32_Sym *sym = &symtab->syms[i];
 		const char *symname = symtab->strtab->data + B32(sym->st_name);
-		if (strcmp(name, symname) != 0)
+		if (strcmp(name, symname) == 0) {
-			continue;
-
-		// only allow retrevial of local variables from the
-		// same object
-		if (sym->st_info >> 4 != STB_GLOBAL && symtab->map != NULL &&
-			obj_idx >= 0) {
-			struct object *obj = symtab->map->meta[i];
-			if (obj->index != (uint32_t)obj_idx)
-				continue;
-		} else if (obj_idx < 0 && sym->st_info >> 4 != STB_GLOBAL) {
-			// when obj_idx is -1, we only want to reutrn
-			// global symbols
-			continue;
-		}
-
 			if (res != NULL)
 				*res = sym;
 			return M_SUCCESS;
 		}
+	}
 	return M_ERROR;
 }
-
-int symtab_map_push(struct symbol_table_mapping *symtabm, struct object *meta)
-{
-	if (symtabm->len >= symtabm->size) {
-		uint32_t size = symtabm->size * 2;
-		void *new = realloc(symtabm->meta,
-		      sizeof(struct object *) * size);
-		if (new == NULL) {
-			PERROR("cannot realloc");
-			return M_ERROR;
-		}
-		symtabm->size = size;
-		symtabm->meta = new;
-	}
-
-	symtabm->meta[symtabm->len++] = meta;
-	return M_SUCCESS;
-}
-
-int symtab_map_init(struct symbol_table_mapping *symtabm)
-{
-	symtabm->len = 0;
-	symtabm->size = SYMTAB_INIT_LEN;
-	symtabm->meta = malloc(sizeof(struct object *) * symtabm->size);
-
-	if (symtabm->meta == NULL) {
-		PERROR("cannot alloc");
-		return M_ERROR;
-	}
-
-	return M_SUCCESS;
-}
-
-
-void symtab_map_free(struct symbol_table_mapping *symtabm)
-{
-	free(symtabm->meta);
-}