Commit 4982223e authored by Rusty Russell's avatar Rusty Russell
Browse files

module: set nx before marking module MODULE_STATE_COMING. 



We currently set RO & NX on modules very late: after we move them from
MODULE_STATE_UNFORMED to MODULE_STATE_COMING, and after we call
parse_args() (which can exec code in the module).

Much better is to do it in complete_formation() and then call
the notifier.

This means that the notifiers will be called on a module which
is already RO & NX, so that may cause problems (ftrace already
changed so they're unaffected).

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent de510989

kernel/module.c

+17 −15
Original line number Original line Diff line number Diff line
@@ -3023,21 +3023,6 @@ static int do_init_module(struct module *mod) 
	 */

	 */

	current->flags &= ~PF_USED_ASYNC;

	current->flags &= ~PF_USED_ASYNC;





	blocking_notifier_call_chain(&module_notify_list,

			MODULE_STATE_COMING, mod);



	/* Set RO and NX regions for core */

	set_section_ro_nx(mod->module_core,

				mod->core_text_size,

				mod->core_ro_size,

				mod->core_size);



	/* Set RO and NX regions for init */

	set_section_ro_nx(mod->module_init,

				mod->init_text_size,

				mod->init_ro_size,

				mod->init_size);



	do_mod_ctors(mod);

	do_mod_ctors(mod);

	/* Start the module */

	/* Start the module */

	if (mod->init != NULL)

	if (mod->init != NULL)
@@ -3168,9 +3153,26 @@ static int complete_formation(struct module *mod, struct load_info *info) 
	/* This relies on module_mutex for list integrity. */

	/* This relies on module_mutex for list integrity. */

	module_bug_finalize(info->hdr, info->sechdrs, mod);

	module_bug_finalize(info->hdr, info->sechdrs, mod);





	/* Set RO and NX regions for core */

	set_section_ro_nx(mod->module_core,

				mod->core_text_size,

				mod->core_ro_size,

				mod->core_size);



	/* Set RO and NX regions for init */

	set_section_ro_nx(mod->module_init,

				mod->init_text_size,

				mod->init_ro_size,

				mod->init_size);



	/* Mark state as coming so strong_try_module_get() ignores us,

	/* Mark state as coming so strong_try_module_get() ignores us,

	 * but kallsyms etc. can see us. */

	 * but kallsyms etc. can see us. */

	mod->state = MODULE_STATE_COMING;

	mod->state = MODULE_STATE_COMING;

	mutex_unlock(&module_mutex);



	blocking_notifier_call_chain(&module_notify_list,

				     MODULE_STATE_COMING, mod);

	return 0;





out:

out:

	mutex_unlock(&module_mutex);

	mutex_unlock(&module_mutex);

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