insmod.c

为samsung2410 ARM移植的busybox工具包

						str = alloca(r - q + 1);
						memcpy(str, q, r - q);

						/* I don't know if it is usefull, as the previous case
						   doesn't null terminate the string ??? */
						str[r - q] = '\0';

						/* Keep next fields */
						q = r;
					} else {
						/* last string */
						str = q;
						q = "";
					}
				}

				if (*p == 's') {
					/* Normal string */
					obj_string_patch(f, sym->secidx, loc - contents, str);
					loc += tgt_sizeof_char_p;
				} else {
					/* Array of chars (in fact, matrix !) */
					unsigned long charssize;	/* size of each member */

					/* Get the size of each member */
					/* Probably we should do that outside the loop ? */
					if (!isdigit(*(p + 1))) {
						error_msg("parameter type 'c' for %s must be followed by"
								" the maximum size", key);
						return 0;
					}
					charssize = strtoul(p + 1, (char **) NULL, 10);

					/* Check length */
					if (strlen(str) >= charssize) {
						error_msg("string too long for %s (max %ld)", key,
								charssize - 1);
						return 0;
					}

					/* Copy to location */
					strcpy((char *) loc, str);
					loc += charssize;
				}
			} else {
				long v = strtoul(q, &q, 0);
				switch (*p) {
				case 'b':
					*loc++ = v;
					break;
				case 'h':
					*(short *) loc = v;
					loc += tgt_sizeof_short;
					break;
				case 'i':
					*(int *) loc = v;
					loc += tgt_sizeof_int;
					break;
				case 'l':
					*(long *) loc = v;
					loc += tgt_sizeof_long;
					break;

				default:
					error_msg("unknown parameter type '%c' for %s", *p, key);
					return 0;
				}
			}

		  retry_end_of_value:
			switch (*q) {
			case '\0':
				goto end_of_arg;

			case ' ':
			case '\t':
			case '\n':
			case '\r':
				++q;
				goto retry_end_of_value;

			case ',':
				if (++n > max) {
					error_msg("too many values for %s (max %d)", key, max);
					return 0;
				}
				++q;
				break;

			default:
				error_msg("invalid argument syntax for %s", key);
				return 0;
			}
		}

	  end_of_arg:
		if (n < min) {
			error_msg("too few values for %s (min %d)", key, min);
			return 0;
		}

		argc--, argv++;
	}

	return 1;
}

#ifdef BB_FEATURE_INSMOD_VERSION_CHECKING
static int new_is_module_checksummed(struct obj_file *f)
{
	const char *p = get_modinfo_value(f, "using_checksums");
	if (p)
		return atoi(p);
	else
		return 0;
}

/* Get the module's kernel version in the canonical integer form.  */

static int
new_get_module_version(struct obj_file *f, char str[STRVERSIONLEN])
{
	char *p, *q;
	int a, b, c;

	p = get_modinfo_value(f, "kernel_version");
	if (p == NULL)
		return -1;
	strncpy(str, p, STRVERSIONLEN);

	a = strtoul(p, &p, 10);
	if (*p != '.')
		return -1;
	b = strtoul(p + 1, &p, 10);
	if (*p != '.')
		return -1;
	c = strtoul(p + 1, &q, 10);
	if (p + 1 == q)
		return -1;

	return a << 16 | b << 8 | c;
}

#endif   /* BB_FEATURE_INSMOD_VERSION_CHECKING */


#ifdef BB_FEATURE_NEW_MODULE_INTERFACE

/* Fetch the loaded modules, and all currently exported symbols.  */

static int new_get_kernel_symbols(void)
{
	char *module_names, *mn;
	struct external_module *modules, *m;
	struct new_module_symbol *syms, *s;
	size_t ret, bufsize, nmod, nsyms, i, j;

	/* Collect the loaded modules.  */

	module_names = xmalloc(bufsize = 256);
  retry_modules_load:
	if (query_module(NULL, QM_MODULES, module_names, bufsize, &ret)) {
		if (errno == ENOSPC && bufsize < ret) {
			module_names = xrealloc(module_names, bufsize = ret);
			goto retry_modules_load;
		}
		perror_msg("QM_MODULES");
		return 0;
	}

	n_ext_modules = nmod = ret;

	/* Collect the modules' symbols.  */

	if (nmod){
		ext_modules = modules = xmalloc(nmod * sizeof(*modules));
		memset(modules, 0, nmod * sizeof(*modules));
		for (i = 0, mn = module_names, m = modules;
			 i < nmod; ++i, ++m, mn += strlen(mn) + 1) {
			struct new_module_info info;
	
			if (query_module(mn, QM_INFO, &info, sizeof(info), &ret)) {
				if (errno == ENOENT) {
					/* The module was removed out from underneath us.  */
					continue;
				}
				perror_msg("query_module: QM_INFO: %s", mn);
				return 0;
			}
	
			syms = xmalloc(bufsize = 1024);
		  retry_mod_sym_load:
			if (query_module(mn, QM_SYMBOLS, syms, bufsize, &ret)) {
				switch (errno) {
				case ENOSPC:
					syms = xrealloc(syms, bufsize = ret);
					goto retry_mod_sym_load;
				case ENOENT:
					/* The module was removed out from underneath us.  */
					continue;
				default:
					perror_msg("query_module: QM_SYMBOLS: %s", mn);
					return 0;
				}
			}
			nsyms = ret;
	
			m->name = mn;
			m->addr = info.addr;
			m->nsyms = nsyms;
			m->syms = syms;
	
			for (j = 0, s = syms; j < nsyms; ++j, ++s) {
				s->name += (unsigned long) syms;
			}
		}
	}

	/* Collect the kernel's symbols.  */

	syms = xmalloc(bufsize = 16 * 1024);
  retry_kern_sym_load:
	if (query_module(NULL, QM_SYMBOLS, syms, bufsize, &ret)) {
		if (errno == ENOSPC && bufsize < ret) {
			syms = xrealloc(syms, bufsize = ret);
			goto retry_kern_sym_load;
		}
		perror_msg("kernel: QM_SYMBOLS");
		return 0;
	}
	nksyms = nsyms = ret;
	ksyms = syms;

	for (j = 0, s = syms; j < nsyms; ++j, ++s) {
		s->name += (unsigned long) syms;
	}
	return 1;
}


/* Return the kernel symbol checksum version, or zero if not used.  */

static int new_is_kernel_checksummed(void)
{
	struct new_module_symbol *s;
	size_t i;

	/* Using_Versions is not the first symbol, but it should be in there.  */

	for (i = 0, s = ksyms; i < nksyms; ++i, ++s)
		if (strcmp((char *) s->name, "Using_Versions") == 0)
			return s->value;

	return 0;
}


static int new_create_this_module(struct obj_file *f, const char *m_name)
{
	struct obj_section *sec;

	sec = obj_create_alloced_section_first(f, ".this", tgt_sizeof_long,
										   sizeof(struct new_module));
	memset(sec->contents, 0, sizeof(struct new_module));

	obj_add_symbol(f, "__this_module", -1,
				   ELFW(ST_INFO) (STB_LOCAL, STT_OBJECT), sec->idx, 0,
				   sizeof(struct new_module));

	obj_string_patch(f, sec->idx, offsetof(struct new_module, name),
					 m_name);

	return 1;
}


static int new_create_module_ksymtab(struct obj_file *f)
{
	struct obj_section *sec;
	int i;

	/* We must always add the module references.  */

	if (n_ext_modules_used) {
		struct new_module_ref *dep;
		struct obj_symbol *tm;

		sec = obj_create_alloced_section(f, ".kmodtab", tgt_sizeof_void_p,
										 (sizeof(struct new_module_ref)
										  * n_ext_modules_used));
		if (!sec)
			return 0;

		tm = obj_find_symbol(f, "__this_module");
		dep = (struct new_module_ref *) sec->contents;
		for (i = 0; i < n_ext_modules; ++i)
			if (ext_modules[i].used) {
				dep->dep = ext_modules[i].addr;
				obj_symbol_patch(f, sec->idx,
								 (char *) &dep->ref - sec->contents, tm);
				dep->next_ref = 0;
				++dep;
			}
	}

	if (flag_export && !obj_find_section(f, "__ksymtab")) {
		size_t nsyms;
		int *loaded;

		sec =
			obj_create_alloced_section(f, "__ksymtab", tgt_sizeof_void_p,
									   0);

		/* We don't want to export symbols residing in sections that
		   aren't loaded.  There are a number of these created so that
		   we make sure certain module options don't appear twice.  */

		loaded = alloca(sizeof(int) * (i = f->header.e_shnum));
		while (--i >= 0)
			loaded[i] = (f->sections[i]->header.sh_flags & SHF_ALLOC) != 0;

		for (nsyms = i = 0; i < HASH_BUCKETS; ++i) {
			struct obj_symbol *sym;
			for (sym = f->symtab[i]; sym; sym = sym->next)
				if (ELFW(ST_BIND) (sym->info) != STB_LOCAL
					&& sym->secidx <= SHN_HIRESERVE
					&& (sym->secidx >= SHN_LORESERVE
						|| loaded[sym->secidx])) {
					ElfW(Addr) ofs = nsyms * 2 * tgt_sizeof_void_p;

					obj_symbol_patch(f, sec->idx, ofs, sym);
					obj_string_patch(f, sec->idx, ofs + tgt_sizeof_void_p,
									 sym->name);

					nsyms++;
				}
		}

		obj_extend_section(sec, nsyms * 2 * tgt_sizeof_char_p);
	}

	return 1;
}


static int
new_init_module(const char *m_name, struct obj_file *f,
				unsigned long m_size)
{
	struct new_module *module;
	struct obj_section *sec;
	void *image;
	int ret;
	tgt_long m_addr;

	sec = obj_find_section(f, ".this");
	if (!sec || !sec->contents) { 
		perror_msg_and_die("corrupt module %s?",m_name);
	}
	module = (struct new_module *) sec->contents;
	m_addr = sec->header.sh_addr;

	module->size_of_struct = sizeof(*module);
	module->size = m_size;
	module->flags = flag_autoclean ? NEW_MOD_AUTOCLEAN : 0;

	sec = obj_find_section(f, "__ksymtab");
	if (sec && sec->header.sh_size) {
		module->syms = sec->header.sh_addr;
		module->nsyms = sec->header.sh_size / (2 * tgt_sizeof_char_p);
	}

	if (n_ext_modules_used) {
		sec = obj_find_section(f, ".kmodtab");
		module->deps = sec->header.sh_addr;
		module->ndeps = n_ext_modules_used;
	}

	module->init =
		obj_symbol_final_value(f, obj_find_symbol(f, "init_module"));
	module->cleanup =
		obj_symbol_final_value(f, obj_find_symbol(f, "cleanup_module"));

	sec = obj_find_section(f, "__ex_table");
	if (sec) {
		module->ex_table_start = sec->header.sh_addr;
		module->ex_table_end = sec->header.sh_addr + sec->header.sh_size;
	}

	sec = obj_find_section(f, ".text.init");
	if (sec) {
		module->runsize = sec->header.sh_addr - m_addr;
	}
	sec = obj_find_section(f, ".data.init");
	if (sec) {
		if (!module->runsize ||
			module->runsize > sec->header.sh_addr - m_addr)
				module->runsize = sec->header.sh_addr - m_addr;
	}
	sec = obj_find_section(f, ARCHDATA_SEC_NAME);
	if (sec && sec->header.sh_size) {
		module->archdata_start = (void*)sec->header.sh_addr;
		module->archdata_end = module->archdata_start + sec->header.sh_size;
	}
	sec = obj_find_section(f, KALLSYMS_SEC_NAME);
	if (sec && sec->header.sh_size) {
		module->kallsyms_start = (void*)sec->header.sh_addr;
		module->kallsyms_end = module->kallsyms_start + sec->header.sh_size;
	}

	if (!arch_init_module(f, module))
		return 0;

	/* Whew!  All of the initialization is complete.  Collect the final
	   module image and give it to the kernel.  */

	image = xmalloc(m_size);
	obj_create_image(f, image);

	ret = new_sys_init_module(m_name, (struct new_module *) image);
	if (ret)
		perror_msg("init_module: %s", m_name);

	free(image);

	return ret == 0;
}

#else

#define new_init_module(x, y, z) TRUE
#define new_create_this_module(x, y) 0
#define new_create_module_ksymtab(x)
#define query_module(v, w, x, y, z) -1

#endif							/* BB_FEATURE_NEW_MODULE_INTERFACE */


/*======================================================================*/

static int
obj_string_patch(struct obj_file *f, int secidx, ElfW(Addr) offset,
				 const char *string)
{
	struct obj_string_patch *p;
	struct obj_section *strsec;
	size_t len = strlen(string) + 1;
	char *loc;

	p = xmalloc(sizeof(*p));
	p->next = f->string_patches;
	p->reloc_secidx = secidx;
	p->reloc_offset = offset;
	f->string_patches = p;

	strsec = obj_find_section(f, ".kstrtab");
	if (strsec == NULL) {
		strsec = obj_create_alloced_section(f, ".kstrtab", 1, len);
		p->string_offset = 0;
		loc = strsec->contents;
	} else {
		p->string_offset = strsec->header.sh_size;
		loc = obj_extend_section(strsec, len);
	}
	memcpy(loc, string, len);

	return 1;
}

static int
obj_symbol_patch(struct obj_file *f, int secidx, ElfW(Addr) offset,
				 struct obj_symbol *sym)
{
	struct obj_symbol_patch *p;

	p = xmalloc(sizeof(*p));
	p->next = f->symbol_patches;
	p->reloc_secidx = secidx;
	p->reloc_offset = offset;
	p->sym = sym;
	f->symbol_patches = p;

	return 1;
}

static int obj_check_undefineds(struct obj_file *f)
{
	unsigned long i;
	int ret = 1;

	for (i = 0; i < HASH_BUCKETS; ++i) {
		struct obj_symbol *sym;
		for (sym = f->symtab[i]; sym; sym = sym->next)
			if (sym->secidx == SHN_UNDEF) {
				if (ELFW(ST_BIND) (sym->info) == STB_WEAK) {
					sym->secidx = SHN_ABS;
					sym->value = 0;
				} else {
					error_msg("unresolved symbol %s", sym->name);
					ret = 0;
				}
			}
	}

	return ret;
}

static void obj_allocate_commons(struct obj_file *f)
{
	struct common_entry {
		struct common_entry *next;
		struct obj_symbol *sym;
	} *common_head = NULL;

	unsigned long i;

	for (i = 0; i < HASH_BUCKETS; ++i) {
		struct obj_symbol *sym;
		for (sym = f->symtab[i]; sym; sym = sym->next)
			if (sym->secidx == SHN_COMMON) {
				/* Collect all COMMON symbols and sort them by size so as to
				   minimize space wasted by alignment requirements.  */
				{
					struct common_entry **p, *n;
					for (p = &common_head; *p; p = &(*p)->next)
						if (sym->size <= (*p)->sym->size)
							break;

					n = alloca(sizeof(*n));
					n->next = *p;
					n->sym = sym;
					*p = n;
				}
			}
	}

	for (i = 1; i < f->local_symtab_size; ++i) {
		struct obj_symbol *sym = f->local_symtab[i];
		if (sym && sym->secidx == SHN_COMMON) {
			struct common_entry **p, *n;
			for (p = &common_head;