Re: [PATCH v4 1/4] modules: split part of complete_formation() into prepare_coming_module()

From: Josh Poimboeuf
Date: Tue Feb 09 2016 - 10:41:44 EST


On Mon, Feb 08, 2016 at 11:50:21PM -0500, Jessica Yu wrote:
> Put all actions that are performed after module->state is set to
> MODULE_STATE_COMING in complete_formation() into a separate function
> prepare_coming_module(). This prepares for the removal of ftrace and
> livepatch module coming notifiers and instead the corresponding work will
> be done in prepare_coming_module(). This split will also allow for
> appropriate error handling.
>
> Signed-off-by: Jessica Yu <jeyu@xxxxxxxxxx>

Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

> ---
> kernel/module.c | 25 ++++++++++++++++++-------
> 1 file changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index 9537da3..a174335 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -3366,6 +3366,14 @@ out_unlocked:
> return err;
> }
>
> +static int prepare_coming_module(struct module *mod)
> +{
> +
> + blocking_notifier_call_chain(&module_notify_list,
> + MODULE_STATE_COMING, mod);
> + return 0;
> +}
> +
> static int complete_formation(struct module *mod, struct load_info *info)
> {
> int err;
> @@ -3389,8 +3397,6 @@ static int complete_formation(struct module *mod, struct load_info *info)
> mod->state = MODULE_STATE_COMING;
> mutex_unlock(&module_mutex);
>
> - blocking_notifier_call_chain(&module_notify_list,
> - MODULE_STATE_COMING, mod);
> return 0;
>
> out:
> @@ -3512,13 +3518,17 @@ static int load_module(struct load_info *info, const char __user *uargs,
> if (err)
> goto ddebug_cleanup;
>
> + err = prepare_coming_module(mod);
> + if (err)
> + goto bug_cleanup;
> +
> /* Module is ready to execute: parsing args may do that. */
> after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
> -32768, 32767, mod,
> unknown_module_param_cb);
> if (IS_ERR(after_dashes)) {
> err = PTR_ERR(after_dashes);
> - goto bug_cleanup;
> + goto coming_cleanup;
> } else if (after_dashes) {
> pr_warn("%s: parameters '%s' after `--' ignored\n",
> mod->name, after_dashes);
> @@ -3527,7 +3537,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
> /* Link in to syfs. */
> err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
> if (err < 0)
> - goto bug_cleanup;
> + goto coming_cleanup;
>
> /* Get rid of temporary copy. */
> free_copy(info);
> @@ -3537,15 +3547,16 @@ static int load_module(struct load_info *info, const char __user *uargs,
>
> return do_init_module(mod);
>
> + coming_cleanup:
> + blocking_notifier_call_chain(&module_notify_list,
> + MODULE_STATE_GOING, mod);
> +
> bug_cleanup:
> /* module_bug_cleanup needs module_mutex protection */
> mutex_lock(&module_mutex);
> module_bug_cleanup(mod);
> mutex_unlock(&module_mutex);
>
> - blocking_notifier_call_chain(&module_notify_list,
> - MODULE_STATE_GOING, mod);
> -
> /* we can't deallocate the module until we clear memory protection */
> module_disable_ro(mod);
> module_disable_nx(mod);
> --
> 2.4.3
>

--
Josh