diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/jump_label.c | 10 | ||||
| -rw-r--r-- | kernel/module.c | 309 | ||||
| -rw-r--r-- | kernel/params.c | 116 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 29 | ||||
| -rw-r--r-- | kernel/workqueue.c | 7 |
5 files changed, 328 insertions, 143 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 9019f15deab2..52ebaca1b9fc 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -302,7 +302,7 @@ static int jump_label_add_module(struct module *mod) continue; key = iterk; - if (__module_address(iter->key) == mod) { + if (within_module(iter->key, mod)) { /* * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH. */ @@ -339,7 +339,7 @@ static void jump_label_del_module(struct module *mod) key = (struct static_key *)(unsigned long)iter->key; - if (__module_address(iter->key) == mod) + if (within_module(iter->key, mod)) continue; prev = &key->next; @@ -443,14 +443,16 @@ static void jump_label_update(struct static_key *key, int enable) { struct jump_entry *stop = __stop___jump_table; struct jump_entry *entry = jump_label_get_entries(key); - #ifdef CONFIG_MODULES - struct module *mod = __module_address((unsigned long)key); + struct module *mod; __jump_label_mod_update(key, enable); + preempt_disable(); + mod = __module_address((unsigned long)key); if (mod) stop = mod->jump_entries + mod->num_jump_entries; + preempt_enable(); #endif /* if there are no users, entry can be NULL */ if (entry) diff --git a/kernel/module.c b/kernel/module.c index f80a97f7da1f..3e0e19763d24 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -101,48 +101,201 @@ DEFINE_MUTEX(module_mutex); EXPORT_SYMBOL_GPL(module_mutex); static LIST_HEAD(modules); -#ifdef CONFIG_KGDB_KDB -struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ -#endif /* CONFIG_KGDB_KDB */ -#ifdef CONFIG_MODULE_SIG -#ifdef CONFIG_MODULE_SIG_FORCE -static bool sig_enforce = true; -#else -static bool sig_enforce = false; +#ifdef CONFIG_MODULES_TREE_LOOKUP + +/* + * Use a latched RB-tree for __module_address(); this allows us to use + * RCU-sched lookups of the address from any context. + * + * Because modules have two address ranges: init and core, we need two + * latch_tree_nodes entries. Therefore we need the back-pointer from + * mod_tree_node. + * + * Because init ranges are short lived we mark them unlikely and have placed + * them outside the critical cacheline in struct module. + * + * This is conditional on PERF_EVENTS || TRACING because those can really hit + * __module_address() hard by doing a lot of stack unwinding; potentially from + * NMI context. + */ -static int param_set_bool_enable_only(const char *val, - const struct kernel_param *kp) +static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) { - int err; - bool test; - struct kernel_param dummy_kp = *kp; + struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node); + struct module *mod = mtn->mod; - dummy_kp.arg = &test; + if (unlikely(mtn == &mod->mtn_init)) + return (unsigned long)mod->module_init; - err = param_set_bool(val, &dummy_kp); - if (err) - return err; + return (unsigned long)mod->module_core; +} + +static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) +{ + struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node); + struct module *mod = mtn->mod; - /* Don't let them unset it once it's set! */ - if (!test && sig_enforce) - return -EROFS; + if (unlikely(mtn == &mod->mtn_init)) + return (unsigned long)mod->init_size; + + return (unsigned long)mod->core_size; +} + +static __always_inline bool +mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) +{ + return __mod_tree_val(a) < __mod_tree_val(b); +} + +static __always_inline int +mod_tree_comp(void *key, struct latch_tree_node *n) +{ + unsigned long val = (unsigned long)key; + unsigned long start, end; + + start = __mod_tree_val(n); + if (val < start) + return -1; + + end = start + __mod_tree_size(n); + if (val >= end) + return 1; - if (test) - sig_enforce = true; return 0; } -static const struct kernel_param_ops param_ops_bool_enable_only = { - .flags = KERNEL_PARAM_OPS_FL_NOARG, - .set = param_set_bool_enable_only, - .get = param_get_bool, +static const struct latch_tree_ops mod_tree_ops = { + .less = mod_tree_less, + .comp = mod_tree_comp, }; -#define param_check_bool_enable_only param_check_bool +static struct mod_tree_root { + struct latch_tree_root root; + unsigned long addr_min; + unsigned long addr_max; +} mod_tree __cacheline_aligned = { + .addr_min = -1UL, +}; + +#define module_addr_min mod_tree.addr_min +#define module_addr_max mod_tree.addr_max + +static noinline void __mod_tree_insert(struct mod_tree_node *node) +{ + latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); +} + +static void __mod_tree_remove(struct mod_tree_node *node) +{ + latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); +} + +/* + * These modifications: insert, remove_init and remove; are serialized by the + * module_mutex. + */ +static void mod_tree_insert(struct module *mod) +{ + mod->mtn_core.mod = mod; + mod->mtn_init.mod = mod; + + __mod_tree_insert(&mod->mtn_core); + if (mod->init_size) + __mod_tree_insert(&mod->mtn_init); +} + +static void mod_tree_remove_init(struct module *mod) +{ + if (mod->init_size) + __mod_tree_remove(&mod->mtn_init); +} + +static void mod_tree_remove(struct module *mod) +{ + __mod_tree_remove(&mod->mtn_core); + mod_tree_remove_init(mod); +} + +static struct module *mod_find(unsigned long addr) +{ + struct latch_tree_node *ltn; + + ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); + if (!ltn) + return NULL; + + return container_of(ltn, struct mod_tree_node, node)->mod; +} + +#else /* MODULES_TREE_LOOKUP */ + +static unsigned long module_addr_min = -1UL, module_addr_max = 0; + +static void mod_tree_insert(struct module *mod) { } +static void mod_tree_remove_init(struct module *mod) { } +static void mod_tree_remove(struct module *mod) { } + +static struct module *mod_find(unsigned long addr) +{ + struct module *mod; + + list_for_each_entry_rcu(mod, &modules, list) { + if (within_module(addr, mod)) + return mod; + } + + return NULL; +} + +#endif /* MODULES_TREE_LOOKUP */ + +/* + * Bounds of module text, for speeding up __module_address. + * Protected by module_mutex. + */ +static void __mod_update_bounds(void *base, unsigned int size) +{ + unsigned long min = (unsigned long)base; + unsigned long max = min + size; + + if (min < module_addr_min) + module_addr_min = min; + if (max > module_addr_max) + module_addr_max = max; +} + +static void mod_update_bounds(struct module *mod) +{ + __mod_update_bounds(mod->module_core, mod->core_size); + if (mod->init_size) + __mod_update_bounds(mod->module_init, mod->init_size); +} + +#ifdef CONFIG_KGDB_KDB +struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ +#endif /* CONFIG_KGDB_KDB */ + +static void module_assert_mutex(void) +{ + lockdep_assert_held(&module_mutex); +} + +static void module_assert_mutex_or_preempt(void) +{ +#ifdef CONFIG_LOCKDEP + if (unlikely(!debug_locks)) + return; + + WARN_ON(!rcu_read_lock_sched_held() && + !lockdep_is_held(&module_mutex)); +#endif +} + +static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); +#ifndef CONFIG_MODULE_SIG_FORCE module_param(sig_enforce, bool_enable_only, 0644); #endif /* !CONFIG_MODULE_SIG_FORCE */ -#endif /* CONFIG_MODULE_SIG */ /* Block module loading/unloading? */ int modules_disabled = 0; @@ -153,10 +306,6 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq); static BLOCKING_NOTIFIER_HEAD(module_notify_list); -/* Bounds of module allocation, for speeding __module_address. - * Protected by module_mutex. */ -static unsigned long module_addr_min = -1UL, module_addr_max = 0; - int register_module_notifier(struct notifier_block *nb) { return blocking_notifier_chain_register(&module_notify_list, nb); @@ -318,6 +467,8 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr, #endif }; + module_assert_mutex_or_preempt(); + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) return true; @@ -457,6 +608,8 @@ static struct module *find_module_all(const char *name, size_t len, { struct module *mod; + module_assert_mutex(); + list_for_each_entry(mod, &modules, list) { if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) continue; @@ -1169,11 +1322,17 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, { const unsigned long *crc; - /* Since this should be found in kernel (which can't be removed), - * no locking is necessary. */ + /* + * Since this should be found in kernel (which can't be removed), no + * locking is necessary -- use preempt_disable() to placate lockdep. + */ + preempt_disable(); if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL, - &crc, true, false)) + &crc, true, false)) { + preempt_enable(); BUG(); + } + preempt_enable(); return check_version(sechdrs, versindex, VMLINUX_SYMBOL_STR(module_layout), mod, crc, NULL); @@ -1661,6 +1820,10 @@ static void mod_sysfs_fini(struct module *mod) mod_kobject_put(mod); } +static void init_param_lock(struct module *mod) +{ + mutex_init(&mod->param_lock); +} #else /* !CONFIG_SYSFS */ static int mod_sysfs_setup(struct module *mod, @@ -1683,6 +1846,9 @@ static void del_usage_links(struct module *mod) { } +static void init_param_lock(struct module *mod) +{ +} #endif /* CONFIG_SYSFS */ static void mod_sysfs_teardown(struct module *mod) @@ -1852,10 +2018,11 @@ static void free_module(struct module *mod) mutex_lock(&module_mutex); /* Unlink carefully: kallsyms could be walking list. */ list_del_rcu(&mod->list); + mod_tree_remove(mod); /* Remove this module from bug list, this uses list_del_rcu */ module_bug_cleanup(mod); - /* Wait for RCU synchronizing before releasing mod->list and buglist. */ - synchronize_rcu(); + /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ + synchronize_sched(); mutex_unlock(&module_mutex); /* This may be NULL, but that's OK */ @@ -2384,22 +2551,6 @@ void * __weak module_alloc(unsigned long size) return vmalloc_exec(size); } -static void *module_alloc_update_bounds(unsigned long size) -{ - void *ret = module_alloc(size); - - if (ret) { - mutex_lock(&module_mutex); - /* Update module bounds. */ - if ((unsigned long)ret < module_addr_min) - module_addr_min = (unsigned long)ret; - if ((unsigned long)ret + size > module_addr_max) - module_addr_max = (unsigned long)ret + size; - mutex_unlock(&module_mutex); - } - return ret; -} - #ifdef CONFIG_DEBUG_KMEMLEAK static void kmemleak_load_module(const struct module *mod, const struct load_info *info) @@ -2805,7 +2956,7 @@ static int move_module(struct module *mod, struct load_info *info) void *ptr; /* Do the allocs. */ - ptr = module_alloc_update_bounds(mod->core_size); + ptr = module_alloc(mod->core_size); /* * The pointer to this block is stored in the module structure * which is inside the block. Just mark it as not being a @@ -2819,7 +2970,7 @@ static int move_module(struct module *mod, struct load_info *info) mod->module_core = ptr; if (mod->init_size) { - ptr = module_alloc_update_bounds(mod->init_size); + ptr = module_alloc(mod->init_size); /* * The pointer to this block is stored in the module structure * which is inside the block. This block doesn't need to be @@ -3119,6 +3270,7 @@ static noinline int do_init_module(struct module *mod) mod->symtab = mod->core_symtab; mod->strtab = mod->core_strtab; #endif + mod_tree_remove_init(mod); unset_module_init_ro_nx(mod); module_arch_freeing_init(mod); mod->module_init = NULL; @@ -3127,11 +3279,11 @@ static noinline int do_init_module(struct module *mod) mod->init_text_size = 0; /* * We want to free module_init, but be aware that kallsyms may be - * walking this with preempt disabled. In all the failure paths, - * we call synchronize_rcu/synchronize_sched, but we don't want - * to slow down the success path, so use actual RCU here. + * walking this with preempt disabled. In all the failure paths, we + * call synchronize_sched(), but we don't want to slow down the success + * path, so use actual RCU here. */ - call_rcu(&freeinit->rcu, do_free_init); + call_rcu_sched(&freeinit->rcu, do_free_init); mutex_unlock(&module_mutex); wake_up_all(&module_wq); @@ -3188,7 +3340,9 @@ again: err = -EEXIST; goto out; } + mod_update_bounds(mod); list_add_rcu(&mod->list, &modules); + mod_tree_insert(mod); err = 0; out: @@ -3304,6 +3458,8 @@ static int load_module(struct load_info *info, const char __user *uargs, if (err) goto unlink_mod; + init_param_lock(mod); + /* Now we've got everything in the final locations, we can * find optional sections. */ err = find_module_sections(mod, info); @@ -3402,8 +3558,8 @@ static int load_module(struct load_info *info, const char __user *uargs, /* Unlink carefully: kallsyms could be walking list. */ list_del_rcu(&mod->list); wake_up_all(&module_wq); - /* Wait for RCU synchronizing before releasing mod->list. */ - synchronize_rcu(); + /* Wait for RCU-sched synchronizing before releasing mod->list. */ + synchronize_sched(); mutex_unlock(&module_mutex); free_module: /* Free lock-classes; relies on the preceding sync_rcu() */ @@ -3527,19 +3683,15 @@ const char *module_address_lookup(unsigned long addr, char **modname, char *namebuf) { - struct module *mod; const char *ret = NULL; + struct module *mod; preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (within_module(addr, mod)) { - if (modname) - *modname = mod->name; - ret = get_ksymbol(mod, addr, size, offset); - break; - } + mod = __module_address(addr); + if (mod) { + if (modname) + *modname = mod->name; + ret = get_ksymbol(mod, addr, size, offset); } /* Make a copy in here where it's safe */ if (ret) { @@ -3547,6 +3699,7 @@ const char *module_address_lookup(unsigned long addr, ret = namebuf; } preempt_enable(); + return ret; } @@ -3670,6 +3823,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned int i; int ret; + module_assert_mutex(); + list_for_each_entry(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; @@ -3844,13 +3999,15 @@ struct module *__module_address(unsigned long addr) if (addr < module_addr_min || addr > module_addr_max) return NULL; - list_for_each_entry_rcu(mod, &modules, list) { + module_assert_mutex_or_preempt(); + + mod = mod_find(addr); + if (mod) { + BUG_ON(!within_module(addr, mod)); if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (within_module(addr, mod)) - return mod; + mod = NULL; } - return NULL; + return mod; } EXPORT_SYMBOL_GPL(__module_address); diff --git a/kernel/params.c b/kernel/params.c index 30288c1e15dd..b6554aa71094 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -25,15 +25,34 @@ #include <linux/slab.h> #include <linux/ctype.h> -/* Protects all parameters, and incidentally kmalloced_param list. */ +#ifdef CONFIG_SYSFS +/* Protects all built-in parameters, modules use their own param_lock */ static DEFINE_MUTEX(param_lock); +/* Use the module's mutex, or if built-in use the built-in mutex */ +#ifdef CONFIG_MODULES +#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) +#else +#define KPARAM_MUTEX(mod) (¶m_lock) +#endif + +static inline void check_kparam_locked(struct module *mod) +{ + BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod))); +} +#else +static inline void check_kparam_locked(struct module *mod) +{ +} +#endif /* !CONFIG_SYSFS */ + /* This just allows us to keep track of which parameters are kmalloced. */ struct kmalloced_param { struct list_head list; char val[]; }; static LIST_HEAD(kmalloced_params); +static DEFINE_SPINLOCK(kmalloced_params_lock); static void *kmalloc_parameter(unsigned int size) { @@ -43,7 +62,10 @@ static void *kmalloc_parameter(unsigned int size) if (!p) return NULL; + spin_lock(&kmalloced_params_lock); list_add(&p->list, &kmalloced_params); + spin_unlock(&kmalloced_params_lock); + return p->val; } @@ -52,6 +74,7 @@ static void maybe_kfree_parameter(void *param) { struct kmalloced_param *p; + spin_lock(&kmalloced_params_lock); list_for_each_entry(p, &kmalloced_params, list) { if (p->val == param) { list_del(&p->list); @@ -59,6 +82,7 @@ static void maybe_kfree_parameter(void *param) break; } } + spin_unlock(&kmalloced_params_lock); } static char dash2underscore(char c) @@ -119,10 +143,10 @@ static int parse_one(char *param, return -EINVAL; pr_debug("handling %s with %p\n", param, params[i].ops->set); - mutex_lock(¶m_lock); + kernel_param_lock(params[i].mod); param_check_unsafe(¶ms[i]); err = params[i].ops->set(val, ¶ms[i]); - mutex_unlock(¶m_lock); + kernel_param_unlock(params[i].mod); return err; } } @@ -254,7 +278,7 @@ char *parse_args(const char *doing, return scnprintf(buffer, PAGE_SIZE, format, \ *((type *)kp->arg)); \ } \ - struct kernel_param_ops param_ops_##name = { \ + const struct kernel_param_ops param_ops_##name = { \ .set = param_set_##name, \ .get = param_get_##name, \ }; \ @@ -306,7 +330,7 @@ static void param_free_charp(void *arg) maybe_kfree_parameter(*((char **)arg)); } -struct kernel_param_ops param_ops_charp = { +const struct kernel_param_ops param_ops_charp = { .set = param_set_charp, .get = param_get_charp, .free = param_free_charp, @@ -331,13 +355,44 @@ int param_get_bool(char *buffer, const struct kernel_param *kp) } EXPORT_SYMBOL(param_get_bool); -struct kernel_param_ops param_ops_bool = { +const struct kernel_param_ops param_ops_bool = { .flags = KERNEL_PARAM_OPS_FL_NOARG, .set = param_set_bool, .get = param_get_bool, }; EXPORT_SYMBOL(param_ops_bool); +int param_set_bool_enable_only(const char *val, const struct kernel_param *kp) +{ + int err = 0; + bool new_value; + bool orig_value = *(bool *)kp->arg; + struct kernel_param dummy_kp = *kp; + + dummy_kp.arg = &new_value; + + err = param_set_bool(val, &dummy_kp); + if (err) + return err; + + /* Don't let them unset it once it's set! */ + if (!new_value && orig_value) + return -EROFS; + + if (new_value) + err = param_set_bool(val, kp); + + return err; +} +EXPORT_SYMBOL_GPL(param_set_bool_enable_only); + +const struct kernel_param_ops param_ops_bool_enable_only = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_bool_enable_only, + .get = param_get_bool, +}; +EXPORT_SYMBOL_GPL(param_ops_bool_enable_only); + /* This one must be bool. */ int param_set_invbool(const char *val, const struct kernel_param *kp) { @@ -359,7 +414,7 @@ int param_get_invbool(char *buffer, const struct kernel_param *kp) } EXPORT_SYMBOL(param_get_invbool); -struct kernel_param_ops param_ops_invbool = { +const struct kernel_param_ops param_ops_invbool = { .set = param_set_invbool, .get = param_get_invbool, }; @@ -367,12 +422,11 @@ EXPORT_SYMBOL(param_ops_invbool); int param_set_bint(const char *val, const struct kernel_param *kp) { - struct kernel_param boolkp; + /* Match bool exactly, by re-using it. */ + struct kernel_param boolkp = *kp; bool v; int ret; - /* Match bool exactly, by re-using it. */ - boolkp = *kp; boolkp.arg = &v; ret = param_set_bool(val, &boolkp); @@ -382,7 +436,7 @@ int param_set_bint(const char *val, const struct kernel_param *kp) } EXPORT_SYMBOL(param_set_bint); -struct kernel_param_ops param_ops_bint = { +const struct kernel_param_ops param_ops_bint = { .flags = KERNEL_PARAM_OPS_FL_NOARG, .set = param_set_bint, .get = param_get_int, @@ -390,7 +444,8 @@ struct kernel_param_ops param_ops_bint = { EXPORT_SYMBOL(param_ops_bint); /* We break the rule and mangle the string. */ -static int param_array(const char *name, +static int param_array(struct module *mod, + const char *name, const char *val, unsigned int min, unsigned int max, void *elem, int elemsize, @@ -421,7 +476,7 @@ static int param_array(const char *name, /* nul-terminate and parse */ save = val[len]; ((char *)val)[len] = '\0'; - BUG_ON(!mutex_is_locked(¶m_lock)); + check_kparam_locked(mod); ret = set(val, &kp); if (ret != 0) @@ -443,7 +498,7 @@ static int param_array_set(const char *val, const struct kernel_param *kp) const struct kparam_array *arr = kp->arr; unsigned int temp_num; - return param_array(kp->name, val, 1, arr->max, arr->elem, + return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem, arr->elemsize, arr->ops->set, kp->level, arr->num ?: &temp_num); } @@ -452,14 +507,13 @@ static int param_array_get(char *buffer, const struct kernel_param *kp) { int i, off, ret; const struct kparam_array *arr = kp->arr; - struct kernel_param p; + struct kernel_param p = *kp; - p = *kp; for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { if (i) buffer[off++] = ','; p.arg = arr->elem + arr->elemsize * i; - BUG_ON(!mutex_is_locked(¶m_lock)); + check_kparam_locked(p.mod); ret = arr->ops->get(buffer + off, &p); if (ret < 0) return ret; @@ -479,7 +533,7 @@ static void param_array_free(void *arg) arr->ops->free(arr->elem + arr->elemsize * i); } -struct kernel_param_ops param_array_ops = { +const struct kernel_param_ops param_array_ops = { .set = param_array_set, .get = param_array_get, .free = param_array_free, @@ -507,7 +561,7 @@ int param_get_string(char *buffer, const struct kernel_param *kp) } EXPORT_SYMBOL(param_get_string); -struct kernel_param_ops param_ops_string = { +const struct kernel_param_ops param_ops_string = { .set = param_set_copystring, .get = param_get_string, }; @@ -542,9 +596,9 @@ static ssize_t param_attr_show(struct module_attribute *mattr, if (!attribute->param->ops->get) return -EPERM; - mutex_lock(¶m_lock); + kernel_param_lock(mk->mod); count = attribute->param->ops->get(buf, attribute->param); - mutex_unlock(¶m_lock); + kernel_param_unlock(mk->mod); if (count > 0) { strcat(buf, "\n"); ++count; @@ -554,7 +608,7 @@ static ssize_t param_attr_show(struct module_attribute *mattr, /* sysfs always hands a nul-terminated string in buf. We rely on that. */ static ssize_t param_attr_store(struct module_attribute *mattr, - struct module_kobject *km, + struct module_kobject *mk, const char *buf, size_t len) { int err; @@ -563,10 +617,10 @@ static ssize_t param_attr_store(struct module_attribute *mattr, if (!attribute->param->ops->set) return -EPERM; - mutex_lock(¶m_lock); + kernel_param_lock(mk->mod); param_check_unsafe(attribute->param); err = attribute->param->ops->set(buf, attribute->param); - mutex_unlock(¶m_lock); + kernel_param_unlock(mk->mod); if (!err) return len; return err; @@ -580,17 +634,18 @@ static ssize_t param_attr_store(struct module_attribute *mattr, #endif #ifdef CONFIG_SYSFS -void __kernel_param_lock(void) +void kernel_param_lock(struct module *mod) { - mutex_lock(¶m_lock); + mutex_lock(KPARAM_MUTEX(mod)); } -EXPORT_SYMBOL(__kernel_param_lock); -void __kernel_param_unlock(void) +void kernel_param_unlock(struct module *mod) { - mutex_unlock(¶m_lock); + mutex_unlock(KPARAM_MUTEX(mod)); } -EXPORT_SYMBOL(__kernel_param_unlock); + +EXPORT_SYMBOL(kernel_param_lock); +EXPORT_SYMBOL(kernel_param_unlock); /* * add_sysfs_param - add a parameter to sysfs @@ -856,6 +911,7 @@ static void __init version_sysfs_builtin(void) mk = locate_module_kobject(vattr->module_name); if (mk) { err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr); + WARN_ON_ONCE(err); kobject_uevent(&mk->kobj, KOBJ_ADD); kobject_put(&mk->kobj); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 30b7a409bf1e..bca3667a2de1 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -319,32 +319,7 @@ static inline s64 timekeeping_get_ns(struct tk_read_base *tkr) * We want to use this from any context including NMI and tracing / * instrumenting the timekeeping code itself. * - * So we handle this differently than the other timekeeping accessor - * functions which retry when the sequence count has changed. The - * update side does: - * - * smp_wmb(); <- Ensure that the last base[1] update is visible - * tkf->seq++; - * smp_wmb(); <- Ensure that the seqcount update is visible - * update(tkf->base[0], tkr); - * smp_wmb(); <- Ensure that the base[0] update is visible - * tkf->seq++; - * smp_wmb(); <- Ensure that the seqcount update is visible - * update(tkf->base[1], tkr); - * - * The reader side does: - * - * do { - * seq = tkf->seq; - * smp_rmb(); - * idx = seq & 0x01; - * now = now(tkf->base[idx]); - * smp_rmb(); - * } while (seq != tkf->seq) - * - * As long as we update base[0] readers are forced off to - * base[1]. Once base[0] is updated readers are redirected to base[0] - * and the base[1] update takes place. + * Employ the latch technique; see @raw_write_seqcount_latch. * * So if a NMI hits the update of base[0] then it will use base[1] * which is still consistent. In the worst case this can result is a @@ -407,7 +382,7 @@ static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf) u64 now; do { - seq = raw_read_seqcount(&tkf->seq); + seq = raw_read_seqcount_latch(&tkf->seq); tkr = tkf->base + (seq & 0x01); now = ktime_to_ns(tkr->base) + timekeeping_get_ns(tkr); } while (read_seqcount_retry(&tkf->seq, seq)); diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5243d4b03087..4c4f06176f74 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -285,12 +285,7 @@ static bool wq_disable_numa; module_param_named(disable_numa, wq_disable_numa, bool, 0444); /* see the comment above the definition of WQ_POWER_EFFICIENT */ -#ifdef CONFIG_WQ_POWER_EFFICIENT_DEFAULT -static bool wq_power_efficient = true; -#else -static bool wq_power_efficient; -#endif - +static bool wq_power_efficient = IS_ENABLED(CONFIG_WQ_POWER_EFFICIENT_DEFAULT); module_param_named(power_efficient, wq_power_efficient, bool, 0444); static bool wq_numa_enabled; /* unbound NUMA affinity enabled */ |