ld: get_dynsym can now resolve references to global symbols

sys/ld/elf.c

@@ -261,16 +261,24 @@ static int parse_phdr(struct elf_image *image)
 }
 
 #if 1
-static elf_sym_t *get_dynsym(struct elf_image *image, size_t index)
+static virt_addr_t get_dynsym(struct elf_image *image, size_t index)
 {
 	elf_sym_t *sym = (elf_sym_t *)(image->e_base + image->e_dynsym
 	                               + (index * image->e_dynsym_entsize));
+	const char *sym_name = (const char *)(image->e_base + image->e_strtab
+	                                      + sym->st_name);
 
-	if (!sym->st_value) {
-		return NULL;
+	if (sym->st_value) {
+		return image->e_base + sym->st_value;
 	}
 
-	return sym;
+	virt_addr_t sym_addr = find_global_symbol(sym_name);
+	if (sym_addr) {
+		return sym_addr;
+	}
+
+	kern_tracef("cannot resolve symbol %s", sym_name);
+	return 0;
 }
 
 static void resolve_symbol(unsigned int slot)
@@ -289,7 +297,7 @@ static int do_rela(struct elf_image *image, elf_rela_t *rela, bool lazy)
 		rela->r_offset);
 #endif
 	int type = ELF64_R_TYPE(rela->r_info);
-	elf_sym_t *sym = NULL;
+	virt_addr_t v = 0;
 
 	switch (type) {
 	case R_X86_64_JUMP_SLOT:
@@ -303,13 +311,13 @@ static int do_rela(struct elf_image *image, elf_rela_t *rela, bool lazy)
 #endif
 		break;
 	case R_X86_64_GLOB_DAT:
-		sym = get_dynsym(image, ELF64_R_SYM(rela->r_info));
-		if (!sym) {
+		v = get_dynsym(image, ELF64_R_SYM(rela->r_info));
+		if (!v) {
 			return ENOEXEC;
 		}
 
 		*(uint64_t *)(image->e_base + rela->r_offset)
-			= image->e_base + sym->st_value + rela->r_addend;
+			= v + rela->r_addend;
 #if 0
 		kern_tracef(
 			"GLOB_DAT: offset=%zx, symbol=%zu, addend=%zx",
@@ -319,13 +327,13 @@ static int do_rela(struct elf_image *image, elf_rela_t *rela, bool lazy)
 #endif
 		break;
 	case R_X86_64_64:
-		sym = get_dynsym(image, ELF64_R_SYM(rela->r_info));
-		if (!sym) {
+		v = get_dynsym(image, ELF64_R_SYM(rela->r_info));
+		if (!v) {
 			return ENOEXEC;
 		}
 
 		*(uint64_t *)(image->e_base + rela->r_offset)
-			= image->e_base + sym->st_value + rela->r_addend;
+			= v + rela->r_addend;
 #if 0
 		kern_tracef(
 			"64: offset=%zx, symbol=%zu, addend=%zx",
@@ -404,6 +412,7 @@ static int relocate_rel(
 	size_t size,
 	size_t entsize)
 {
+	kern_tracef("relocate_rel (unsupported)");
 	return ENOEXEC;
 }
 
@@ -624,16 +633,19 @@ int elf_image_load(struct elf_image *img)
 
 	int e = reserve_exec_region(img);
 	if (e != SUCCESS) {
+		kern_log("error 1");
 		return e;
 	}
 
 	e = map_image(img);
 	if (e != SUCCESS) {
+		kern_log("error 2");
 		return e;
 	}
 
 	e = elf_image_parse_dynamic(img);
 	if (e != SUCCESS) {
+		kern_log("error 3");
 		return e;
 	}