7 files changed, 116 insertions, 200 deletions
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index d09b46ef032f..626cf8668a7e 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -124,17 +124,6 @@ char *module_next_tag_pair(char *string, unsigned long *secsize);
 #define for_each_modinfo_entry(entry, info, name) \
 	for (entry = get_modinfo(info, name); entry; entry = get_next_modinfo(info, name, entry))
 
-static inline void module_assert_mutex_or_preempt(void)
-{
-#ifdef CONFIG_LOCKDEP
-	if (unlikely(!debug_locks))
-		return;
-
-	WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
-		     !lockdep_is_held(&module_mutex));
-#endif
-}
-
 static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
 {
 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index bf65e0c3c86f..00a60796327c 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -177,19 +177,15 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
 	unsigned long strtab_size;
 	void *data_base = mod->mem[MOD_DATA].base;
 	void *init_data_base = mod->mem[MOD_INIT_DATA].base;
+	struct mod_kallsyms *kallsyms;
 
-	/* Set up to point into init section. */
-	mod->kallsyms = (void __rcu *)init_data_base +
-		info->mod_kallsyms_init_off;
+	kallsyms = init_data_base + info->mod_kallsyms_init_off;
 
-	rcu_read_lock();
-	/* The following is safe since this pointer cannot change */
-	rcu_dereference(mod->kallsyms)->symtab = (void *)symsec->sh_addr;
-	rcu_dereference(mod->kallsyms)->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
+	kallsyms->symtab = (void *)symsec->sh_addr;
+	kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
 	/* Make sure we get permanent strtab: don't use info->strtab. */
-	rcu_dereference(mod->kallsyms)->strtab =
-		(void *)info->sechdrs[info->index.str].sh_addr;
-	rcu_dereference(mod->kallsyms)->typetab = init_data_base + info->init_typeoffs;
+	kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
+	kallsyms->typetab = init_data_base + info->init_typeoffs;
 
 	/*
 	 * Now populate the cut down core kallsyms for after init
@@ -199,20 +195,19 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
 	mod->core_kallsyms.strtab = s = data_base + info->stroffs;
 	mod->core_kallsyms.typetab = data_base + info->core_typeoffs;
 	strtab_size = info->core_typeoffs - info->stroffs;
-	src = rcu_dereference(mod->kallsyms)->symtab;
-	for (ndst = i = 0; i < rcu_dereference(mod->kallsyms)->num_symtab; i++) {
-		rcu_dereference(mod->kallsyms)->typetab[i] = elf_type(src + i, info);
+	src = kallsyms->symtab;
+	for (ndst = i = 0; i < kallsyms->num_symtab; i++) {
+		kallsyms->typetab[i] = elf_type(src + i, info);
 		if (i == 0 || is_livepatch_module(mod) ||
 		    is_core_symbol(src + i, info->sechdrs, info->hdr->e_shnum,
 				   info->index.pcpu)) {
 			ssize_t ret;
 
 			mod->core_kallsyms.typetab[ndst] =
-			    rcu_dereference(mod->kallsyms)->typetab[i];
+				kallsyms->typetab[i];
 			dst[ndst] = src[i];
 			dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
-			ret = strscpy(s,
-				      &rcu_dereference(mod->kallsyms)->strtab[src[i].st_name],
+			ret = strscpy(s, &kallsyms->strtab[src[i].st_name],
 				      strtab_size);
 			if (ret < 0)
 				break;
@@ -220,7 +215,9 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
 			strtab_size -= ret + 1;
 		}
 	}
-	rcu_read_unlock();
+
+	/* Set up to point into init section. */
+	rcu_assign_pointer(mod->kallsyms, kallsyms);
 	mod->core_kallsyms.num_symtab = ndst;
 }
 
@@ -260,7 +257,7 @@ static const char *find_kallsyms_symbol(struct module *mod,
 {
 	unsigned int i, best = 0;
 	unsigned long nextval, bestval;
-	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+	struct mod_kallsyms *kallsyms = rcu_dereference(mod->kallsyms);
 	struct module_memory *mod_mem;
 
 	/* At worse, next value is at end of module */
@@ -319,7 +316,7 @@ void * __weak dereference_module_function_descriptor(struct module *mod,
 
 /*
  * For kallsyms to ask for address resolution.  NULL means not found.  Careful
- * not to lock to avoid deadlock on oopses, simply disable preemption.
+ * not to lock to avoid deadlock on oopses, RCU is enough.
  */
 int module_address_lookup(unsigned long addr,
 			  unsigned long *size,
@@ -332,7 +329,7 @@ int module_address_lookup(unsigned long addr,
 	int ret = 0;
 	struct module *mod;
 
-	preempt_disable();
+	guard(rcu)();
 	mod = __module_address(addr);
 	if (mod) {
 		if (modname)
@@ -350,8 +347,6 @@ int module_address_lookup(unsigned long addr,
 		if (sym)
 			ret = strscpy(namebuf, sym, KSYM_NAME_LEN);
 	}
-	preempt_enable();
-
 	return ret;
 }
 
@@ -359,7 +354,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname)
 {
 	struct module *mod;
 
-	preempt_disable();
+	guard(rcu)();
 	list_for_each_entry_rcu(mod, &modules, list) {
 		if (mod->state == MODULE_STATE_UNFORMED)
 			continue;
@@ -371,12 +366,10 @@ int lookup_module_symbol_name(unsigned long addr, char *symname)
 				goto out;
 
 			strscpy(symname, sym, KSYM_NAME_LEN);
-			preempt_enable();
 			return 0;
 		}
 	}
 out:
-	preempt_enable();
 	return -ERANGE;
 }
 
@@ -385,13 +378,13 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 {
 	struct module *mod;
 
-	preempt_disable();
+	guard(rcu)();
 	list_for_each_entry_rcu(mod, &modules, list) {
 		struct mod_kallsyms *kallsyms;
 
 		if (mod->state == MODULE_STATE_UNFORMED)
 			continue;
-		kallsyms = rcu_dereference_sched(mod->kallsyms);
+		kallsyms = rcu_dereference(mod->kallsyms);
 		if (symnum < kallsyms->num_symtab) {
 			const Elf_Sym *sym = &kallsyms->symtab[symnum];
 
@@ -400,12 +393,10 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 			strscpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
 			strscpy(module_name, mod->name, MODULE_NAME_LEN);
 			*exported = is_exported(name, *value, mod);
-			preempt_enable();
 			return 0;
 		}
 		symnum -= kallsyms->num_symtab;
 	}
-	preempt_enable();
 	return -ERANGE;
 }
 
@@ -413,7 +404,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 static unsigned long __find_kallsyms_symbol_value(struct module *mod, const char *name)
 {
 	unsigned int i;
-	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+	struct mod_kallsyms *kallsyms = rcu_dereference(mod->kallsyms);
 
 	for (i = 0; i < kallsyms->num_symtab; i++) {
 		const Elf_Sym *sym = &kallsyms->symtab[i];
@@ -453,23 +444,15 @@ static unsigned long __module_kallsyms_lookup_name(const char *name)
 /* Look for this name: can be of form module:name. */
 unsigned long module_kallsyms_lookup_name(const char *name)
 {
-	unsigned long ret;
-
 	/* Don't lock: we're in enough trouble already. */
-	preempt_disable();
-	ret = __module_kallsyms_lookup_name(name);
-	preempt_enable();
-	return ret;
+	guard(rcu)();
+	return __module_kallsyms_lookup_name(name);
 }
 
 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
 {
-	unsigned long ret;
-
-	preempt_disable();
-	ret = __find_kallsyms_symbol_value(mod, name);
-	preempt_enable();
-	return ret;
+	guard(rcu)();
+	return __find_kallsyms_symbol_value(mod, name);
 }
 
 int module_kallsyms_on_each_symbol(const char *modname,
@@ -490,10 +473,8 @@ int module_kallsyms_on_each_symbol(const char *modname,
 		if (modname && strcmp(modname, mod->name))
 			continue;
 
-		/* Use rcu_dereference_sched() to remain compliant with the sparse tool */
-		preempt_disable();
-		kallsyms = rcu_dereference_sched(mod->kallsyms);
-		preempt_enable();
+		kallsyms = rcu_dereference_check(mod->kallsyms,
+						 lockdep_is_held(&module_mutex));
 
 		for (i = 0; i < kallsyms->num_symtab; i++) {
 			const Elf_Sym *sym = &kallsyms->symtab[i];
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 1fb9ad289a6f..a2859dc3eea6 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -67,7 +67,7 @@
 
 /*
  * Mutex protects:
- * 1) List of modules (also safely readable with preempt_disable),
+ * 1) List of modules (also safely readable within RCU read section),
  * 2) module_use links,
  * 3) mod_tree.addr_min/mod_tree.addr_max.
  * (delete and add uses RCU list operations).
@@ -331,7 +331,7 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
 
 /*
  * Find an exported symbol and return it, along with, (optional) crc and
- * (optional) module which owns it.  Needs preempt disabled or module_mutex.
+ * (optional) module which owns it. Needs RCU or module_mutex.
  */
 bool find_symbol(struct find_symbol_arg *fsa)
 {
@@ -345,8 +345,6 @@ bool find_symbol(struct find_symbol_arg *fsa)
 	struct module *mod;
 	unsigned int i;
 
-	module_assert_mutex_or_preempt();
-
 	for (i = 0; i < ARRAY_SIZE(arr); i++)
 		if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
 			return true;
@@ -374,16 +372,14 @@ bool find_symbol(struct find_symbol_arg *fsa)
 }
 
 /*
- * Search for module by name: must hold module_mutex (or preempt disabled
- * for read-only access).
+ * Search for module by name: must hold module_mutex (or RCU for read-only
+ * access).
  */
 struct module *find_module_all(const char *name, size_t len,
 			       bool even_unformed)
 {
 	struct module *mod;
 
-	module_assert_mutex_or_preempt();
-
 	list_for_each_entry_rcu(mod, &modules, list,
 				lockdep_is_held(&module_mutex)) {
 		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
@@ -454,8 +450,7 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 	struct module *mod;
 	unsigned int cpu;
 
-	preempt_disable();
-
+	guard(rcu)();
 	list_for_each_entry_rcu(mod, &modules, list) {
 		if (mod->state == MODULE_STATE_UNFORMED)
 			continue;
@@ -472,13 +467,10 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 						per_cpu_ptr(mod->percpu,
 							    get_boot_cpu_id());
 				}
-				preempt_enable();
 				return true;
 			}
 		}
 	}
-
-	preempt_enable();
 	return false;
 }
 
@@ -795,8 +787,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 	async_synchronize_full();
 
 	/* Store the name and taints of the last unloaded module for diagnostic purposes */
-	strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
-	strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
+	strscpy(last_unloaded_module.name, mod->name);
+	strscpy(last_unloaded_module.taints, module_flags(mod, buf, false));
 
 	free_module(mod);
 	/* someone could wait for the module in add_unformed_module() */
@@ -814,10 +806,9 @@ void __symbol_put(const char *symbol)
 		.gplok	= true,
 	};
 
-	preempt_disable();
+	guard(rcu)();
 	BUG_ON(!find_symbol(&fsa));
 	module_put(fsa.owner);
-	preempt_enable();
 }
 EXPORT_SYMBOL(__symbol_put);
 
@@ -832,13 +823,12 @@ void symbol_put_addr(void *addr)
 
 	/*
 	 * Even though we hold a reference on the module; we still need to
-	 * disable preemption in order to safely traverse the data structure.
+	 * RCU read section in order to safely traverse the data structure.
 	 */
-	preempt_disable();
+	guard(rcu)();
 	modaddr = __module_text_address(a);
 	BUG_ON(!modaddr);
 	module_put(modaddr);
-	preempt_enable();
 }
 EXPORT_SYMBOL_GPL(symbol_put_addr);
 
@@ -1189,7 +1179,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
 
 getname:
 	/* We must make copy under the lock if we failed to get ref. */
-	strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
+	strscpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
 unlock:
 	mutex_unlock(&module_mutex);
 	return fsa.sym;
@@ -1221,18 +1211,6 @@ void __weak module_arch_freeing_init(struct module *mod)
 {
 }
 
-void *__module_writable_address(struct module *mod, void *loc)
-{
-	for_class_mod_mem_type(type, text) {
-		struct module_memory *mem = &mod->mem[type];
-
-		if (loc >= mem->base && loc < mem->base + mem->size)
-			return loc + (mem->rw_copy - mem->base);
-	}
-
-	return loc;
-}
-
 static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
 {
 	unsigned int size = PAGE_ALIGN(mod->mem[type].size);
@@ -1250,21 +1228,15 @@ static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
 	if (!ptr)
 		return -ENOMEM;
 
-	mod->mem[type].base = ptr;
-
 	if (execmem_is_rox(execmem_type)) {
-		ptr = vzalloc(size);
+		int err = execmem_make_temp_rw(ptr, size);
 
-		if (!ptr) {
-			execmem_free(mod->mem[type].base);
+		if (err) {
+			execmem_free(ptr);
 			return -ENOMEM;
 		}
 
-		mod->mem[type].rw_copy = ptr;
 		mod->mem[type].is_rox = true;
-	} else {
-		mod->mem[type].rw_copy = mod->mem[type].base;
-		memset(mod->mem[type].base, 0, size);
 	}
 
 	/*
@@ -1278,18 +1250,29 @@ static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
 	 * *do* eventually get freed, but let's just keep things simple
 	 * and avoid *any* false positives.
 	 */
-	kmemleak_not_leak(ptr);
+	if (!mod->mem[type].is_rox)
+		kmemleak_not_leak(ptr);
+
+	memset(ptr, 0, size);
+	mod->mem[type].base = ptr;
 
 	return 0;
 }
 
+static void module_memory_restore_rox(struct module *mod)
+{
+	for_class_mod_mem_type(type, text) {
+		struct module_memory *mem = &mod->mem[type];
+
+		if (mem->is_rox)
+			execmem_restore_rox(mem->base, mem->size);
+	}
+}
+
 static void module_memory_free(struct module *mod, enum mod_mem_type type)
 {
 	struct module_memory *mem = &mod->mem[type];
 
-	if (mem->is_rox)
-		vfree(mem->rw_copy);
-
 	execmem_free(mem->base);
 }
 
@@ -1348,7 +1331,7 @@ static void free_module(struct module *mod)
 	mod_tree_remove(mod);
 	/* Remove this module from bug list, this uses list_del_rcu */
 	module_bug_cleanup(mod);
-	/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
+	/* Wait for RCU synchronizing before releasing mod->list and buglist. */
 	synchronize_rcu();
 	if (try_add_tainted_module(mod))
 		pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
@@ -1371,21 +1354,18 @@ void *__symbol_get(const char *symbol)
 		.warn	= true,
 	};
 
-	preempt_disable();
-	if (!find_symbol(&fsa))
-		goto fail;
-	if (fsa.license != GPL_ONLY) {
-		pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
-			symbol);
-		goto fail;
+	scoped_guard(rcu) {
+		if (!find_symbol(&fsa))
+			return NULL;
+		if (fsa.license != GPL_ONLY) {
+			pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
+				symbol);
+			return NULL;
+		}
+		if (strong_try_module_get(fsa.owner))
+			return NULL;
 	}
-	if (strong_try_module_get(fsa.owner))
-		goto fail;
-	preempt_enable();
 	return (void *)kernel_symbol_value(fsa.sym);
-fail:
-	preempt_enable();
-	return NULL;
 }
 EXPORT_SYMBOL_GPL(__symbol_get);
 
@@ -2642,7 +2622,6 @@ static int move_module(struct module *mod, struct load_info *info)
 	for_each_mod_mem_type(type) {
 		if (!mod->mem[type].size) {
 			mod->mem[type].base = NULL;
-			mod->mem[type].rw_copy = NULL;
 			continue;
 		}
 
@@ -2659,7 +2638,6 @@ static int move_module(struct module *mod, struct load_info *info)
 		void *dest;
 		Elf_Shdr *shdr = &info->sechdrs[i];
 		const char *sname;
-		unsigned long addr;
 
 		if (!(shdr->sh_flags & SHF_ALLOC))
 			continue;
@@ -2680,14 +2658,12 @@ static int move_module(struct module *mod, struct load_info *info)
 				ret = PTR_ERR(dest);
 				goto out_err;
 			}
-			addr = (unsigned long)dest;
 			codetag_section_found = true;
 		} else {
 			enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
 			unsigned long offset = shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK;
 
-			addr = (unsigned long)mod->mem[type].base + offset;
-			dest = mod->mem[type].rw_copy + offset;
+			dest = mod->mem[type].base + offset;
 		}
 
 		if (shdr->sh_type != SHT_NOBITS) {
@@ -2710,13 +2686,14 @@ static int move_module(struct module *mod, struct load_info *info)
 		 * users of info can keep taking advantage and using the newly
 		 * minted official memory area.
 		 */
-		shdr->sh_addr = addr;
+		shdr->sh_addr = (unsigned long)dest;
 		pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
 			 (long)shdr->sh_size, info->secstrings + shdr->sh_name);
 	}
 
 	return 0;
 out_err:
+	module_memory_restore_rox(mod);
 	for (t--; t >= 0; t--)
 		module_memory_free(mod, t);
 	if (codetag_section_found)
@@ -2863,17 +2840,8 @@ int __weak module_finalize(const Elf_Ehdr *hdr,
 	return 0;
 }
 
-int __weak module_post_finalize(const Elf_Ehdr *hdr,
-				const Elf_Shdr *sechdrs,
-				struct module *me)
-{
-	return 0;
-}
-
 static int post_relocation(struct module *mod, const struct load_info *info)
 {
-	int ret;
-
 	/* Sort exception table now relocations are done. */
 	sort_extable(mod->extable, mod->extable + mod->num_exentries);
 
@@ -2885,24 +2853,7 @@ static int post_relocation(struct module *mod, const struct load_info *info)
 	add_kallsyms(mod, info);
 
 	/* Arch-specific module finalizing. */
-	ret = module_finalize(info->hdr, info->sechdrs, mod);
-	if (ret)
-		return ret;
-
-	for_each_mod_mem_type(type) {
-		struct module_memory *mem = &mod->mem[type];
-
-		if (mem->is_rox) {
-			if (!execmem_update_copy(mem->base, mem->rw_copy,
-						 mem->size))
-				return -ENOMEM;
-
-			vfree(mem->rw_copy);
-			mem->rw_copy = NULL;
-		}
-	}
-
-	return module_post_finalize(info->hdr, info->sechdrs, mod);
+	return module_finalize(info->hdr, info->sechdrs, mod);
 }
 
 /* Call module constructors. */
@@ -3049,7 +3000,7 @@ static noinline int do_init_module(struct module *mod)
 #endif
 	/*
 	 * We want to free module_init, but be aware that kallsyms may be
-	 * walking this with preempt disabled.  In all the failure paths, we
+	 * walking this within an RCU read section. In all the failure paths, we
 	 * call synchronize_rcu(), but we don't want to slow down the success
 	 * path. execmem_free() cannot be called in an interrupt, so do the
 	 * work and call synchronize_rcu() in a work queue.
@@ -3499,6 +3450,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 				       mod->mem[type].size);
 	}
 
+	module_memory_restore_rox(mod);
 	module_deallocate(mod, info);
  free_copy:
 	/*
@@ -3715,28 +3667,23 @@ out:
 /* Given an address, look for it in the module exception tables. */
 const struct exception_table_entry *search_module_extables(unsigned long addr)
 {
-	const struct exception_table_entry *e = NULL;
 	struct module *mod;
 
-	preempt_disable();
+	guard(rcu)();
 	mod = __module_address(addr);
 	if (!mod)
-		goto out;
+		return NULL;
 
 	if (!mod->num_exentries)
-		goto out;
-
-	e = search_extable(mod->extable,
-			   mod->num_exentries,
-			   addr);
-out:
-	preempt_enable();
-
+		return NULL;
 	/*
-	 * Now, if we found one, we are running inside it now, hence
-	 * we cannot unload the module, hence no refcnt needed.
+	 * The address passed here belongs to a module that is currently
+	 * invoked (we are running inside it). Therefore its module::refcnt
+	 * needs already be >0 to ensure that it is not removed at this stage.
+	 * All other user need to invoke this function within a RCU read
+	 * section.
 	 */
-	return e;
+	return search_extable(mod->extable, mod->num_exentries, addr);
 }
 
 /**
@@ -3748,20 +3695,15 @@ out:
  */
 bool is_module_address(unsigned long addr)
 {
-	bool ret;
-
-	preempt_disable();
-	ret = __module_address(addr) != NULL;
-	preempt_enable();
-
-	return ret;
+	guard(rcu)();
+	return __module_address(addr) != NULL;
 }
 
 /**
  * __module_address() - get the module which contains an address.
  * @addr: the address.
  *
- * Must be called with preempt disabled or module mutex held so that
+ * Must be called within RCU read section or module mutex held so that
  * module doesn't get freed during this.
  */
 struct module *__module_address(unsigned long addr)
@@ -3779,8 +3721,6 @@ struct module *__module_address(unsigned long addr)
 	return NULL;
 
 lookup:
-	module_assert_mutex_or_preempt();
-
 	mod = mod_find(addr, &mod_tree);
 	if (mod) {
 		BUG_ON(!within_module(addr, mod));
@@ -3800,20 +3740,28 @@ lookup:
  */
 bool is_module_text_address(unsigned long addr)
 {
-	bool ret;
+	guard(rcu)();
+	return __module_text_address(addr) != NULL;
+}
 
-	preempt_disable();
-	ret = __module_text_address(addr) != NULL;
-	preempt_enable();
+void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data)
+{
+	struct module *mod;
 
-	return ret;
+	guard(rcu)();
+	list_for_each_entry_rcu(mod, &modules, list) {
+		if (mod->state == MODULE_STATE_UNFORMED)
+			continue;
+		if (func(mod, data))
+			break;
+	}
 }
 
 /**
  * __module_text_address() - get the module whose code contains an address.
  * @addr: the address.
  *
- * Must be called with preempt disabled or module mutex held so that
+ * Must be called within RCU read section or module mutex held so that
  * module doesn't get freed during this.
  */
 struct module *__module_text_address(unsigned long addr)
@@ -3836,7 +3784,7 @@ void print_modules(void)
 
 	printk(KERN_DEFAULT "Modules linked in:");
 	/* Most callers should already have preempt disabled, but make sure */
-	preempt_disable();
+	guard(rcu)();
 	list_for_each_entry_rcu(mod, &modules, list) {
 		if (mod->state == MODULE_STATE_UNFORMED)
 			continue;
@@ -3844,7 +3792,6 @@ void print_modules(void)
 	}
 
 	print_unloaded_tainted_modules();
-	preempt_enable();
 	if (last_unloaded_module.name[0])
 		pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
 			last_unloaded_module.taints);
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
index 74834ba15615..03f4142cfbf4 100644
--- a/kernel/module/strict_rwx.c
+++ b/kernel/module/strict_rwx.c
@@ -9,6 +9,7 @@
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 #include <linux/set_memory.h>
+#include <linux/execmem.h>
 #include "internal.h"
 
 static int module_set_memory(const struct module *mod, enum mod_mem_type type,
@@ -32,12 +33,12 @@ static int module_set_memory(const struct module *mod, enum mod_mem_type type,
 int module_enable_text_rox(const struct module *mod)
 {
 	for_class_mod_mem_type(type, text) {
+		const struct module_memory *mem = &mod->mem[type];
 		int ret;
 
-		if (mod->mem[type].is_rox)
-			continue;
-
-		if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
+		if (mem->is_rox)
+			ret = execmem_restore_rox(mem->base, mem->size);
+		else if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
 			ret = module_set_memory(mod, type, set_memory_rox);
 		else
 			ret = module_set_memory(mod, type, set_memory_x);
diff --git a/kernel/module/tracking.c b/kernel/module/tracking.c
index 16742d1c630c..4fefec5b683c 100644
--- a/kernel/module/tracking.c
+++ b/kernel/module/tracking.c
@@ -21,8 +21,6 @@ int try_add_tainted_module(struct module *mod)
 {
 	struct mod_unload_taint *mod_taint;
 
-	module_assert_mutex_or_preempt();
-
 	if (!mod->taints)
 		goto out;
 
diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
index 277197977d43..d3204c5c74eb 100644
--- a/kernel/module/tree_lookup.c
+++ b/kernel/module/tree_lookup.c
@@ -12,11 +12,11 @@
 
 /*
  * Use a latched RB-tree for __module_address(); this allows us to use
- * RCU-sched lookups of the address from any context.
+ * RCU lookups of the address from any context.
  *
- * 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.
+ * This is conditional on PERF_EVENTS || TRACING || CFI_CLANG because those can
+ * really hit __module_address() hard by doing a lot of stack unwinding;
+ * potentially from NMI context.
  */
 
 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
diff --git a/kernel/module/version.c b/kernel/module/version.c
index 3718a8868321..2beefeba82d9 100644
--- a/kernel/module/version.c
+++ b/kernel/module/version.c
@@ -79,17 +79,17 @@ int check_modstruct_version(const struct load_info *info,
 		.name	= "module_layout",
 		.gplok	= true,
 	};
+	bool have_symbol;
 
 	/*
 	 * Since this should be found in kernel (which can't be removed), no
-	 * locking is necessary -- use preempt_disable() to placate lockdep.
+	 * locking is necessary. Regardless use a RCU read section to keep
+	 * lockdep happy.
 	 */
-	preempt_disable();
-	if (!find_symbol(&fsa)) {
-		preempt_enable();
-		BUG();
-	}
-	preempt_enable();
+	scoped_guard(rcu)
+		have_symbol = find_symbol(&fsa);
+	BUG_ON(!have_symbol);
+
 	return check_version(info, "module_layout", mod, fsa.crc);
 }