diff options
| -rw-r--r-- | kernel/jump_label.c | 88 |
1 files changed, 38 insertions, 50 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 72707e44c44d..2e7cc1e4b4b5 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -54,12 +54,7 @@ jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL); } -static void jump_label_update(struct static_key *key, int enable); - -static inline bool static_key_type(struct static_key *key) -{ - return (unsigned long)key->entries & JUMP_TYPE_MASK; -} +static void jump_label_update(struct static_key *key); void static_key_slow_inc(struct static_key *key) { @@ -68,13 +63,8 @@ void static_key_slow_inc(struct static_key *key) return; jump_label_lock(); - if (atomic_read(&key->enabled) == 0) { - if (!static_key_type(key)) - jump_label_update(key, JUMP_LABEL_JMP); - else - jump_label_update(key, JUMP_LABEL_NOP); - } - atomic_inc(&key->enabled); + if (atomic_inc_return(&key->enabled) == 1) + jump_label_update(key); jump_label_unlock(); } EXPORT_SYMBOL_GPL(static_key_slow_inc); @@ -92,10 +82,7 @@ static void __static_key_slow_dec(struct static_key *key, atomic_inc(&key->enabled); schedule_delayed_work(work, rate_limit); } else { - if (!static_key_type(key)) - jump_label_update(key, JUMP_LABEL_NOP); - else - jump_label_update(key, JUMP_LABEL_JMP); + jump_label_update(key); } jump_label_unlock(); } @@ -154,7 +141,7 @@ static int __jump_label_text_reserved(struct jump_entry *iter_start, return 0; } -/* +/* * Update code which is definitely not currently executing. * Architectures which need heavyweight synchronization to modify * running code can override this to make the non-live update case @@ -163,29 +150,17 @@ static int __jump_label_text_reserved(struct jump_entry *iter_start, void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry *entry, enum jump_label_type type) { - arch_jump_label_transform(entry, type); + arch_jump_label_transform(entry, type); } -static void __jump_label_update(struct static_key *key, - struct jump_entry *entry, - struct jump_entry *stop, int enable) +static inline struct jump_entry *static_key_entries(struct static_key *key) { - for (; (entry < stop) && - (entry->key == (jump_label_t)(unsigned long)key); - entry++) { - /* - * entry->code set to 0 invalidates module init text sections - * kernel_text_address() verifies we are not in core kernel - * init code, see jump_label_invalidate_module_init(). - */ - if (entry->code && kernel_text_address(entry->code)) - arch_jump_label_transform(entry, enable); - } + return (struct jump_entry *)((unsigned long)key->entries & ~JUMP_TYPE_MASK); } -static inline struct jump_entry *static_key_entries(struct static_key *key) +static inline bool static_key_type(struct static_key *key) { - return (struct jump_entry *)((unsigned long)key->entries & ~JUMP_TYPE_MASK); + return (unsigned long)key->entries & JUMP_TYPE_MASK; } static inline struct static_key *jump_entry_key(struct jump_entry *entry) @@ -193,14 +168,30 @@ static inline struct static_key *jump_entry_key(struct jump_entry *entry) return (struct static_key *)((unsigned long)entry->key); } -static enum jump_label_type jump_label_type(struct static_key *key) +static enum jump_label_type jump_label_type(struct jump_entry *entry) { + struct static_key *key = jump_entry_key(entry); bool enabled = static_key_enabled(key); bool type = static_key_type(key); return enabled ^ type; } +static void __jump_label_update(struct static_key *key, + struct jump_entry *entry, + struct jump_entry *stop) +{ + for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) { + /* + * entry->code set to 0 invalidates module init text sections + * kernel_text_address() verifies we are not in core kernel + * init code, see jump_label_invalidate_module_init(). + */ + if (entry->code && kernel_text_address(entry->code)) + arch_jump_label_transform(entry, jump_label_type(entry)); + } +} + void __init jump_label_init(void) { struct jump_entry *iter_start = __start___jump_table; @@ -214,8 +205,8 @@ void __init jump_label_init(void) for (iter = iter_start; iter < iter_stop; iter++) { struct static_key *iterk; + arch_jump_label_transform_static(iter, jump_label_type(iter)); iterk = jump_entry_key(iter); - arch_jump_label_transform_static(iter, jump_label_type(iterk)); if (iterk == key) continue; @@ -255,17 +246,15 @@ static int __jump_label_mod_text_reserved(void *start, void *end) start, end); } -static void __jump_label_mod_update(struct static_key *key, int enable) +static void __jump_label_mod_update(struct static_key *key) { - struct static_key_mod *mod = key->next; + struct static_key_mod *mod; - while (mod) { + for (mod = key->next; mod; mod = mod->next) { struct module *m = mod->mod; __jump_label_update(key, mod->entries, - m->jump_entries + m->num_jump_entries, - enable); - mod = mod->next; + m->jump_entries + m->num_jump_entries); } } @@ -287,9 +276,8 @@ void jump_label_apply_nops(struct module *mod) if (iter_start == iter_stop) return; - for (iter = iter_start; iter < iter_stop; iter++) { + for (iter = iter_start; iter < iter_stop; iter++) arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); - } } static int jump_label_add_module(struct module *mod) @@ -330,8 +318,8 @@ static int jump_label_add_module(struct module *mod) jlm->next = key->next; key->next = jlm; - if (jump_label_type(key) == JUMP_LABEL_JMP) - __jump_label_update(key, iter, iter_stop, JUMP_LABEL_JMP); + if (jump_label_type(iter) == JUMP_LABEL_JMP) + __jump_label_update(key, iter, iter_stop); } return 0; @@ -451,14 +439,14 @@ int jump_label_text_reserved(void *start, void *end) return ret; } -static void jump_label_update(struct static_key *key, int enable) +static void jump_label_update(struct static_key *key) { struct jump_entry *stop = __stop___jump_table; struct jump_entry *entry = static_key_entries(key); #ifdef CONFIG_MODULES struct module *mod; - __jump_label_mod_update(key, enable); + __jump_label_mod_update(key); preempt_disable(); mod = __module_address((unsigned long)key); @@ -468,7 +456,7 @@ static void jump_label_update(struct static_key *key, int enable) #endif /* if there are no users, entry can be NULL */ if (entry) - __jump_label_update(key, entry, stop, enable); + __jump_label_update(key, entry, stop); } #endif |