From 4c973d1620ae08f5cbe27644c5f5b974c8f594ec Mon Sep 17 00:00:00 2001 From: Jessica Yu Date: Wed, 16 Mar 2016 20:55:38 -0400 Subject: modules: split part of complete_formation() into prepare_coming_module() Put all actions in complete_formation() that are performed after module->state is set to MODULE_STATE_COMING into a separate function prepare_coming_module(). This split prepares for the removal of the livepatch module notifiers in favor of hard-coding function calls to klp_module_{coming,going} in the module loader. The complete_formation -> prepare_coming_module split will also make error handling easier since we can jump to the appropriate error label to do any module GOING cleanup after all the COMING-actions have completed. Signed-off-by: Jessica Yu Reviewed-by: Josh Poimboeuf Reviewed-by: Petr Mladek Acked-by: Rusty Russell Signed-off-by: Jiri Kosina --- kernel/module.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 794ebe8e878d..6dbfad415d51 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3392,9 +3392,6 @@ static int complete_formation(struct module *mod, struct load_info *info) mod->state = MODULE_STATE_COMING; mutex_unlock(&module_mutex); - ftrace_module_enable(mod); - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_COMING, mod); return 0; out: @@ -3402,6 +3399,14 @@ out: return err; } +static int prepare_coming_module(struct module *mod) +{ + ftrace_module_enable(mod); + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_COMING, mod); + return 0; +} + static int unknown_module_param_cb(char *param, char *val, const char *modname, void *arg) { @@ -3516,13 +3521,17 @@ 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); @@ -3531,7 +3540,7 @@ 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); @@ -3541,15 +3550,16 @@ 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); -- cgit From 7e545d6eca20ce8ef7f66a63146cbff82b2ba760 Mon Sep 17 00:00:00 2001 From: Jessica Yu Date: Wed, 16 Mar 2016 20:55:39 -0400 Subject: livepatch/module: remove livepatch module notifier Remove the livepatch module notifier in favor of directly enabling and disabling patches to modules in the module loader. Hard-coding the function calls ensures that ftrace_module_enable() is run before klp_module_coming() during module load, and that klp_module_going() is run before ftrace_release_mod() during module unload. This way, ftrace and livepatch code is run in the correct order during the module load/unload sequence without dependence on the module notifier call chain. Signed-off-by: Jessica Yu Reviewed-by: Petr Mladek Acked-by: Josh Poimboeuf Acked-by: Rusty Russell Signed-off-by: Jiri Kosina --- kernel/module.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 6dbfad415d51..4b65fbb10bdc 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -53,6 +53,7 @@ #include #include #include +#include #include #include #include @@ -984,6 +985,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, mod->exit(); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); + klp_module_going(mod); ftrace_release_mod(mod); async_synchronize_full(); @@ -3315,6 +3317,7 @@ fail: module_put(mod); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); + klp_module_going(mod); ftrace_release_mod(mod); free_module(mod); wake_up_all(&module_wq); @@ -3401,7 +3404,13 @@ out: static int prepare_coming_module(struct module *mod) { + int err; + ftrace_module_enable(mod); + err = klp_module_coming(mod); + if (err) + return err; + blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); return 0; @@ -3553,6 +3562,7 @@ static int load_module(struct load_info *info, const char __user *uargs, coming_cleanup: blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); + klp_module_going(mod); bug_cleanup: /* module_bug_cleanup needs module_mutex protection */ -- cgit