Commit 0d21b0e3 authored by Rusty Russell's avatar Rusty Russell
Browse files

module: add new state MODULE_STATE_UNFORMED. 



You should never look at such a module, so it's excised from all paths
which traverse the modules list.

We add the state at the end, to avoid gratuitous ABI break (ksplice).

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 52441fa8

include/linux/module.h

+5 −5
Original line number Diff line number Diff line
@@ -199,11 +199,11 @@ struct module_use { 
	struct module *source, *target;

};



enum module_state

{

	MODULE_STATE_LIVE,

	MODULE_STATE_COMING,

	MODULE_STATE_GOING,

enum module_state {

	MODULE_STATE_LIVE,	/* Normal state. */

	MODULE_STATE_COMING,	/* Full formed, running module_init. */

	MODULE_STATE_GOING,	/* Going away. */

	MODULE_STATE_UNFORMED,	/* Still setting it up. */

};



/**

kernel/debug/kdb/kdb_main.c

+2 −0
Original line number Diff line number Diff line
@@ -1970,6 +1970,8 @@ static int kdb_lsmod(int argc, const char **argv) 


	kdb_printf("Module                  Size  modstruct     Used by\n");

	list_for_each_entry(mod, kdb_modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;



		kdb_printf("%-20s%8u  0x%p ", mod->name,

			   mod->core_size, (void *)mod);

kernel/module.c

+52 −5
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ struct load_info { 
   ongoing or failed initialization etc. */

static inline int strong_try_module_get(struct module *mod)

{

	BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);

	if (mod && mod->state == MODULE_STATE_COMING)

		return -EBUSY;

	if (try_module_get(mod))
@@ -343,6 +344,9 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr, 
#endif

		};



		if (mod->state == MODULE_STATE_UNFORMED)

			continue;



		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))

			return true;

	}
@@ -450,16 +454,24 @@ const struct kernel_symbol *find_symbol(const char *name, 
EXPORT_SYMBOL_GPL(find_symbol);



/* Search for module by name: must hold module_mutex. */

struct module *find_module(const char *name)

static struct module *find_module_all(const char *name,

				      bool even_unformed)

{

	struct module *mod;



	list_for_each_entry(mod, &modules, list) {

		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (strcmp(mod->name, name) == 0)

			return mod;

	}

	return NULL;

}



struct module *find_module(const char *name)

{

	return find_module_all(name, false);

}

EXPORT_SYMBOL_GPL(find_module);



#ifdef CONFIG_SMP
@@ -525,6 +537,8 @@ bool is_module_percpu_address(unsigned long addr) 
	preempt_disable();



	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (!mod->percpu_size)

			continue;

		for_each_possible_cpu(cpu) {
@@ -1048,6 +1062,8 @@ static ssize_t show_initstate(struct module_attribute *mattr, 
	case MODULE_STATE_GOING:

		state = "going";

		break;

	default:

		BUG();

	}

	return sprintf(buffer, "%s\n", state);

}
@@ -1786,6 +1802,8 @@ void set_all_modules_text_rw(void) 


	mutex_lock(&module_mutex);

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if ((mod->module_core) && (mod->core_text_size)) {

			set_page_attributes(mod->module_core,

						mod->module_core + mod->core_text_size,
@@ -1807,6 +1825,8 @@ void set_all_modules_text_ro(void) 


	mutex_lock(&module_mutex);

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if ((mod->module_core) && (mod->core_text_size)) {

			set_page_attributes(mod->module_core,

						mod->module_core + mod->core_text_size,
@@ -2998,7 +3018,8 @@ static bool finished_loading(const char *name) 


	mutex_lock(&module_mutex);

	mod = find_module(name);

	ret = !mod || mod->state != MODULE_STATE_COMING;

	ret = !mod || mod->state == MODULE_STATE_LIVE

		|| mod->state == MODULE_STATE_GOING;

	mutex_unlock(&module_mutex);



	return ret;
@@ -3361,6 +3382,8 @@ const char *module_address_lookup(unsigned long addr, 


	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (within_module_init(addr, mod) ||

		    within_module_core(addr, mod)) {

			if (modname)
@@ -3384,6 +3407,8 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) 


	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (within_module_init(addr, mod) ||

		    within_module_core(addr, mod)) {

			const char *sym;
@@ -3408,6 +3433,8 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, 


	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (within_module_init(addr, mod) ||

		    within_module_core(addr, mod)) {

			const char *sym;
@@ -3435,6 +3462,8 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 


	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (symnum < mod->num_symtab) {

			*value = mod->symtab[symnum].st_value;

			*type = mod->symtab[symnum].st_info;
@@ -3477,10 +3506,13 @@ unsigned long module_kallsyms_lookup_name(const char *name) 
			ret = mod_find_symname(mod, colon+1);

		*colon = ':';

	} else {

		list_for_each_entry_rcu(mod, &modules, list)

		list_for_each_entry_rcu(mod, &modules, list) {

			if (mod->state == MODULE_STATE_UNFORMED)

				continue;

			if ((ret = mod_find_symname(mod, name)) != 0)

				break;

		}

	}

	preempt_enable();

	return ret;

}
@@ -3494,6 +3526,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, 
	int ret;



	list_for_each_entry(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		for (i = 0; i < mod->num_symtab; i++) {

			ret = fn(data, mod->strtab + mod->symtab[i].st_name,

				 mod, mod->symtab[i].st_value);
@@ -3509,6 +3543,7 @@ static char *module_flags(struct module *mod, char *buf) 
{

	int bx = 0;



	BUG_ON(mod->state == MODULE_STATE_UNFORMED);

	if (mod->taints ||

	    mod->state == MODULE_STATE_GOING ||

	    mod->state == MODULE_STATE_COMING) {
@@ -3550,6 +3585,10 @@ static int m_show(struct seq_file *m, void *p) 
	struct module *mod = list_entry(p, struct module, list);

	char buf[8];



	/* We always ignore unformed modules. */

	if (mod->state == MODULE_STATE_UNFORMED)

		return 0;



	seq_printf(m, "%s %u",

		   mod->name, mod->init_size + mod->core_size);

	print_unload_info(m, mod);
@@ -3610,6 +3649,8 @@ const struct exception_table_entry *search_module_extables(unsigned long addr) 


	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (mod->num_exentries == 0)

			continue;
@@ -3658,10 +3699,13 @@ struct module *__module_address(unsigned long addr) 
	if (addr < module_addr_min || addr > module_addr_max)

		return NULL;



	list_for_each_entry_rcu(mod, &modules, list)

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		if (within_module_core(addr, mod)

		    || within_module_init(addr, mod))

			return mod;

	}

	return NULL;

}

EXPORT_SYMBOL_GPL(__module_address);
@@ -3714,8 +3758,11 @@ void print_modules(void) 
	printk(KERN_DEFAULT "Modules linked in:");

	/* Most callers should already have preempt disabled, but make sure */

	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list)

	list_for_each_entry_rcu(mod, &modules, list) {

		if (mod->state == MODULE_STATE_UNFORMED)

			continue;

		printk(" %s%s", mod->name, module_flags(mod, buf));

	}

	preempt_enable();

	if (last_unloaded_module[0])

		printk(" [last unloaded: %s]", last_unloaded_module);