diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/jump_label.c | 77 | ||||
| -rw-r--r-- | kernel/kprobes.c | 26 |
2 files changed, 82 insertions, 21 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 7be868bf25c6..3b79bd938330 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -39,6 +39,16 @@ struct jump_label_module_entry { struct module *mod; }; +void jump_label_lock(void) +{ + mutex_lock(&jump_label_mutex); +} + +void jump_label_unlock(void) +{ + mutex_unlock(&jump_label_mutex); +} + static int jump_label_cmp(const void *a, const void *b) { const struct jump_entry *jea = a; @@ -152,7 +162,7 @@ void jump_label_update(unsigned long key, enum jump_label_type type) struct jump_label_module_entry *e_module; int count; - mutex_lock(&jump_label_mutex); + jump_label_lock(); entry = get_jump_label_entry((jump_label_t)key); if (entry) { count = entry->nr_entries; @@ -168,13 +178,14 @@ void jump_label_update(unsigned long key, enum jump_label_type type) count = e_module->nr_entries; iter = e_module->table; while (count--) { - if (kernel_text_address(iter->code)) + if (iter->key && + kernel_text_address(iter->code)) arch_jump_label_transform(iter, type); iter++; } } } - mutex_unlock(&jump_label_mutex); + jump_label_unlock(); } static int addr_conflict(struct jump_entry *entry, void *start, void *end) @@ -231,6 +242,7 @@ out: * overlaps with any of the jump label patch addresses. Code * that wants to modify kernel text should first verify that * it does not overlap with any of the jump label addresses. + * Caller must hold jump_label_mutex. * * returns 1 if there is an overlap, 0 otherwise */ @@ -241,7 +253,6 @@ int jump_label_text_reserved(void *start, void *end) struct jump_entry *iter_stop = __start___jump_table; int conflict = 0; - mutex_lock(&jump_label_mutex); iter = iter_start; while (iter < iter_stop) { if (addr_conflict(iter, start, end)) { @@ -256,10 +267,16 @@ int jump_label_text_reserved(void *start, void *end) conflict = module_conflict(start, end); #endif out: - mutex_unlock(&jump_label_mutex); return conflict; } +/* + * Not all archs need this. + */ +void __weak arch_jump_label_text_poke_early(jump_label_t addr) +{ +} + static __init int init_jump_label(void) { int ret; @@ -267,7 +284,7 @@ static __init int init_jump_label(void) struct jump_entry *iter_stop = __stop___jump_table; struct jump_entry *iter; - mutex_lock(&jump_label_mutex); + jump_label_lock(); ret = build_jump_label_hashtable(__start___jump_table, __stop___jump_table); iter = iter_start; @@ -275,7 +292,7 @@ static __init int init_jump_label(void) arch_jump_label_text_poke_early(iter->code); iter++; } - mutex_unlock(&jump_label_mutex); + jump_label_unlock(); return ret; } early_initcall(init_jump_label); @@ -366,6 +383,39 @@ static void remove_jump_label_module(struct module *mod) } } +static void remove_jump_label_module_init(struct module *mod) +{ + struct hlist_head *head; + struct hlist_node *node, *node_next, *module_node, *module_node_next; + struct jump_label_entry *e; + struct jump_label_module_entry *e_module; + struct jump_entry *iter; + int i, count; + + /* if the module doesn't have jump label entries, just return */ + if (!mod->num_jump_entries) + return; + + for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { + head = &jump_label_table[i]; + hlist_for_each_entry_safe(e, node, node_next, head, hlist) { + hlist_for_each_entry_safe(e_module, module_node, + module_node_next, + &(e->modules), hlist) { + if (e_module->mod != mod) + continue; + count = e_module->nr_entries; + iter = e_module->table; + while (count--) { + if (within_module_init(iter->code, mod)) + iter->key = 0; + iter++; + } + } + } + } +} + static int jump_label_module_notify(struct notifier_block *self, unsigned long val, void *data) @@ -375,16 +425,21 @@ jump_label_module_notify(struct notifier_block *self, unsigned long val, switch (val) { case MODULE_STATE_COMING: - mutex_lock(&jump_label_mutex); + jump_label_lock(); ret = add_jump_label_module(mod); if (ret) remove_jump_label_module(mod); - mutex_unlock(&jump_label_mutex); + jump_label_unlock(); break; case MODULE_STATE_GOING: - mutex_lock(&jump_label_mutex); + jump_label_lock(); remove_jump_label_module(mod); - mutex_unlock(&jump_label_mutex); + jump_label_unlock(); + break; + case MODULE_STATE_LIVE: + jump_label_lock(); + remove_jump_label_module_init(mod); + jump_label_unlock(); break; } return ret; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 99865c33a60d..9737a76e106f 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1145,14 +1145,13 @@ int __kprobes register_kprobe(struct kprobe *p) if (ret) return ret; + jump_label_lock(); preempt_disable(); if (!kernel_text_address((unsigned long) p->addr) || in_kprobes_functions((unsigned long) p->addr) || ftrace_text_reserved(p->addr, p->addr) || - jump_label_text_reserved(p->addr, p->addr)) { - preempt_enable(); - return -EINVAL; - } + jump_label_text_reserved(p->addr, p->addr)) + goto fail_with_jump_label; /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ p->flags &= KPROBE_FLAG_DISABLED; @@ -1166,10 +1165,9 @@ int __kprobes register_kprobe(struct kprobe *p) * We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. */ - if (unlikely(!try_module_get(probed_mod))) { - preempt_enable(); - return -EINVAL; - } + if (unlikely(!try_module_get(probed_mod))) + goto fail_with_jump_label; + /* * If the module freed .init.text, we couldn't insert * kprobes in there. @@ -1177,16 +1175,18 @@ int __kprobes register_kprobe(struct kprobe *p) if (within_module_init((unsigned long)p->addr, probed_mod) && probed_mod->state != MODULE_STATE_COMING) { module_put(probed_mod); - preempt_enable(); - return -EINVAL; + goto fail_with_jump_label; } } preempt_enable(); + jump_label_unlock(); p->nmissed = 0; INIT_LIST_HEAD(&p->list); mutex_lock(&kprobe_mutex); + jump_label_lock(); /* needed to call jump_label_text_reserved() */ + get_online_cpus(); /* For avoiding text_mutex deadlock. */ mutex_lock(&text_mutex); @@ -1214,12 +1214,18 @@ int __kprobes register_kprobe(struct kprobe *p) out: mutex_unlock(&text_mutex); put_online_cpus(); + jump_label_unlock(); mutex_unlock(&kprobe_mutex); if (probed_mod) module_put(probed_mod); return ret; + +fail_with_jump_label: + preempt_enable(); + jump_label_unlock(); + return -EINVAL; } EXPORT_SYMBOL_GPL(register_kprobe); |