Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux (d790be38) · Commits · 戴 / test

include/linux/module.h

+1 −15

Original line number	Diff line number	Diff line
		@@ -210,20 +210,6 @@ enum module_state {
		MODULE_STATE_UNFORMED, /* Still setting it up. */
		};

		/**
		* struct module_ref - per cpu module reference counts
		* @incs: number of module get on this cpu
		* @decs: number of module put on this cpu
		*
		* We force an alignment on 8 or 16 bytes, so that alloc_percpu()
		* put @incs/@decs in same cache line, with no extra memory cost,
		* since alloc_percpu() is fine grained.
		*/
		struct module_ref {
		unsigned long incs;
		unsigned long decs;
		} __attribute((aligned(2 * sizeof(unsigned long))));

		struct module {
		enum module_state state;

		@@ -367,7 +353,7 @@ struct module {
		/* Destruction function. */
		void (*exit)(void);

		struct module_ref __percpu *refptr;
		atomic_t refcnt;
		#endif

		#ifdef CONFIG_CONSTRUCTORS

include/trace/events/module.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -80,7 +80,7 @@ DECLARE_EVENT_CLASS(module_refcnt,

		TP_fast_assign(
		__entry->ip = ip;
		__entry->refcnt = __this_cpu_read(mod->refptr->incs) - __this_cpu_read(mod->refptr->decs);
		__entry->refcnt = atomic_read(&mod->refcnt);
		__assign_str(name, mod->name);
		),

kernel/module.c

+75 −95

Original line number	Diff line number	Diff line
		@@ -42,7 +42,6 @@
		#include <linux/vermagic.h>
		#include <linux/notifier.h>
		#include <linux/sched.h>
		#include <linux/stop_machine.h>
		#include <linux/device.h>
		#include <linux/string.h>
		#include <linux/mutex.h>
		@@ -98,7 +97,7 @@
		* 1) List of modules (also safely readable with preempt_disable),
		* 2) module_use links,
		* 3) module_addr_min/module_addr_max.
		* (delete uses stop_machine/add uses RCU list operations). */
		* (delete and add uses RCU list operations). */
		DEFINE_MUTEX(module_mutex);
		EXPORT_SYMBOL_GPL(module_mutex);
		static LIST_HEAD(modules);
		@@ -628,18 +627,23 @@ static char last_unloaded_module[MODULE_NAME_LEN+1];

		EXPORT_TRACEPOINT_SYMBOL(module_get);

		/* MODULE_REF_BASE is the base reference count by kmodule loader. */
		#define MODULE_REF_BASE 1

		/* Init the unload section of the module. */
		static int module_unload_init(struct module *mod)
		{
		mod->refptr = alloc_percpu(struct module_ref);
		if (!mod->refptr)
		return -ENOMEM;
		/*
		* Initialize reference counter to MODULE_REF_BASE.
		* refcnt == 0 means module is going.
		*/
		atomic_set(&mod->refcnt, MODULE_REF_BASE);

		INIT_LIST_HEAD(&mod->source_list);
		INIT_LIST_HEAD(&mod->target_list);

		/* Hold reference count during initialization. */
		raw_cpu_write(mod->refptr->incs, 1);
		atomic_inc(&mod->refcnt);

		return 0;
		}
		@@ -721,8 +725,6 @@ static void module_unload_free(struct module *mod)
		kfree(use);
		}
		mutex_unlock(&module_mutex);

		free_percpu(mod->refptr);
		}

		#ifdef CONFIG_MODULE_FORCE_UNLOAD
		@@ -740,60 +742,39 @@ static inline int try_force_unload(unsigned int flags)
		}
		#endif /* CONFIG_MODULE_FORCE_UNLOAD */

		struct stopref
		/* Try to release refcount of module, 0 means success. */
		static int try_release_module_ref(struct module *mod)
		{
		struct module *mod;
		int flags;
		int *forced;
		};
		int ret;

		/* Whole machine is stopped with interrupts off when this runs. */
		static int __try_stop_module(void *_sref)
		{
		struct stopref *sref = _sref;
		/* Try to decrement refcnt which we set at loading */
		ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
		BUG_ON(ret < 0);
		if (ret)
		/* Someone can put this right now, recover with checking */
		ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);

		return ret;
		}

		static int try_stop_module(struct module mod, int flags, int forced)
		{
		/* If it's not unused, quit unless we're forcing. */
		if (module_refcount(sref->mod) != 0) {
		if (!(*sref->forced = try_force_unload(sref->flags)))
		if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
		return -EWOULDBLOCK;
		}

		/* Mark it as dying. */
		sref->mod->state = MODULE_STATE_GOING;
		return 0;
		}

		static int try_stop_module(struct module mod, int flags, int forced)
		{
		struct stopref sref = { mod, flags, forced };
		mod->state = MODULE_STATE_GOING;

		return stop_machine(__try_stop_module, &sref, NULL);
		return 0;
		}

		unsigned long module_refcount(struct module *mod)
		{
		unsigned long incs = 0, decs = 0;
		int cpu;

		for_each_possible_cpu(cpu)
		decs += per_cpu_ptr(mod->refptr, cpu)->decs;
		/*
		* ensure the incs are added up after the decs.
		* module_put ensures incs are visible before decs with smp_wmb.
		*
		* This 2-count scheme avoids the situation where the refcount
		* for CPU0 is read, then CPU0 increments the module refcount,
		* then CPU1 drops that refcount, then the refcount for CPU1 is
		* read. We would record a decrement but not its corresponding
		* increment so we would see a low count (disaster).
		*
		* Rare situation? But module_refcount can be preempted, and we
		* might be tallying up 4096+ CPUs. So it is not impossible.
		*/
		smp_rmb();
		for_each_possible_cpu(cpu)
		incs += per_cpu_ptr(mod->refptr, cpu)->incs;
		return incs - decs;
		return (unsigned long)atomic_read(&mod->refcnt) - MODULE_REF_BASE;
		}
		EXPORT_SYMBOL(module_refcount);

		@@ -877,8 +858,10 @@ static inline void print_unload_info(struct seq_file m, struct module mod)

		seq_printf(m, " %lu ", module_refcount(mod));

		/* Always include a trailing , so userspace can differentiate
		between this and the old multi-field proc format. */
		/*
		* Always include a trailing , so userspace can differentiate
		* between this and the old multi-field proc format.
		*/
		list_for_each_entry(use, &mod->source_list, source_list) {
		printed_something = 1;
		seq_printf(m, "%s,", use->source->name);
		@@ -886,11 +869,11 @@ static inline void print_unload_info(struct seq_file m, struct module mod)

		if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
		seq_printf(m, "[permanent],");
		seq_puts(m, "[permanent],");
		}

		if (!printed_something)
		seq_printf(m, "-");
		seq_puts(m, "-");
		}

		void __symbol_put(const char *symbol)
		@@ -935,7 +918,7 @@ void __module_get(struct module *module)
		{
		if (module) {
		preempt_disable();
		__this_cpu_inc(module->refptr->incs);
		atomic_inc(&module->refcnt);
		trace_module_get(module, _RET_IP_);
		preempt_enable();
		}
		@@ -948,11 +931,11 @@ bool try_module_get(struct module *module)

		if (module) {
		preempt_disable();

		if (likely(module_is_live(module))) {
		__this_cpu_inc(module->refptr->incs);
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
		atomic_inc_not_zero(&module->refcnt) != 0))
		trace_module_get(module, _RET_IP_);
		} else
		else
		ret = false;

		preempt_enable();
		@@ -963,11 +946,12 @@ EXPORT_SYMBOL(try_module_get);

		void module_put(struct module *module)
		{
		int ret;

		if (module) {
		preempt_disable();
		smp_wmb(); /* see comment in module_refcount */
		__this_cpu_inc(module->refptr->decs);

		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0); /* Failed to put refcount */
		trace_module_put(module, _RET_IP_);
		preempt_enable();
		}
		@@ -978,7 +962,7 @@ EXPORT_SYMBOL(module_put);
		static inline void print_unload_info(struct seq_file m, struct module mod)
		{
		/* We don't know the usage count, or what modules are using. */
		seq_printf(m, " - -");
		seq_puts(m, " - -");
		}

		static inline void module_unload_free(struct module *mod)
		@@ -1165,7 +1149,7 @@ static int check_version(Elf_Shdr *sechdrs,
		return 0;

		bad_version:
		printk("%s: disagrees about version of symbol %s\n",
		pr_warn("%s: disagrees about version of symbol %s\n",
		mod->name, symname);
		return 0;
		}
		@@ -1288,15 +1272,13 @@ static inline bool sect_empty(const Elf_Shdr *sect)
		return !(sect->sh_flags & SHF_ALLOC) \|\| sect->sh_size == 0;
		}

		struct module_sect_attr
		{
		struct module_sect_attr {
		struct module_attribute mattr;
		char *name;
		unsigned long address;
		};

		struct module_sect_attrs
		{
		struct module_sect_attrs {
		struct attribute_group grp;
		unsigned int nsections;
		struct module_sect_attr attrs[0];
		@@ -1550,7 +1532,8 @@ static int module_add_modinfo_attrs(struct module *mod)
		(attr->test && attr->test(mod))) {
		memcpy(temp_attr, attr, sizeof(*temp_attr));
		sysfs_attr_init(&temp_attr->attr);
		error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
		error = sysfs_create_file(&mod->mkobj.kobj,
		&temp_attr->attr);
		++temp_attr;
		}
		}
		@@ -1697,18 +1680,6 @@ static void mod_sysfs_teardown(struct module *mod)
		mod_sysfs_fini(mod);
		}

		/*
		* unlink the module with the whole machine is stopped with interrupts off
		* - this defends against kallsyms not taking locks
		*/
		static int __unlink_module(void *_mod)
		{
		struct module *mod = _mod;
		list_del(&mod->list);
		module_bug_cleanup(mod);
		return 0;
		}

		#ifdef CONFIG_DEBUG_SET_MODULE_RONX
		/*
		* LKM RO/NX protection: protect module's text/ro-data
		@@ -1860,7 +1831,12 @@ static void free_module(struct module *mod)

		/* Now we can delete it from the lists */
		mutex_lock(&module_mutex);
		stop_machine(__unlink_module, mod, NULL);
		/* Unlink carefully: kallsyms could be walking list. */
		list_del_rcu(&mod->list);
		/* 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();
		mutex_unlock(&module_mutex);

		/* This may be NULL, but that's OK */
		@@ -1955,7 +1931,7 @@ static int simplify_symbols(struct module mod, const struct load_info info)
		/* We compiled with -fno-common. These are not
		supposed to happen. */
		pr_debug("Common symbol: %s\n", name);
		printk("%s: please compile with -fno-common\n",
		pr_warn("%s: please compile with -fno-common\n",
		mod->name);
		ret = -ENOEXEC;
		break;
		@@ -2735,7 +2711,7 @@ static int find_module_sections(struct module mod, struct load_info info)
		* This shouldn't happen with same compiler and binutils
		* building all parts of the module.
		*/
		printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",
		pr_warn("%s: has both .ctors and .init_array.\n",
		mod->name);
		return -EINVAL;
		}
		@@ -3023,8 +2999,10 @@ static int do_init_module(struct module *mod)
		if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
		if (ret < 0) {
		/* Init routine failed: abort. Try to protect us from
		buggy refcounters. */
		/*
		* Init routine failed: abort. Try to protect us from
		* buggy refcounters.
		*/
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		module_put(mod);
		@@ -3352,6 +3330,8 @@ 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();
		mutex_unlock(&module_mutex);
		free_module:
		module_deallocate(mod, info);
		@@ -3695,7 +3675,7 @@ static int m_show(struct seq_file m, void p)
		if (mod->taints)
		seq_printf(m, " %s", module_flags(mod, buf));

		seq_printf(m, "\n");
		seq_puts(m, "\n");
		return 0;
		}

kernel/params.c

+46 −51

Original line number	Diff line number	Diff line
		@@ -603,73 +603,66 @@ static __modinit int add_sysfs_param(struct module_kobject *mk,
		const struct kernel_param *kp,
		const char *name)
		{
		struct module_param_attrs *new;
		struct attribute **attrs;
		int err, num;
		struct module_param_attrs *new_mp;
		struct attribute **new_attrs;
		unsigned int i;

		/* We don't bother calling this with invisible parameters. */
		BUG_ON(!kp->perm);

		if (!mk->mp) {
		num = 0;
		attrs = NULL;
		} else {
		num = mk->mp->num;
		attrs = mk->mp->grp.attrs;
		/* First allocation. */
		mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
		if (!mk->mp)
		return -ENOMEM;
		mk->mp->grp.name = "parameters";
		/* NULL-terminated attribute array. */
		mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
		GFP_KERNEL);
		/* Caller will cleanup via free_module_param_attrs */
		if (!mk->mp->grp.attrs)
		return -ENOMEM;
		}

		/* Enlarge. */
		new = krealloc(mk->mp,
		sizeof(mk->mp) + sizeof(mk->mp->attrs[0]) (num+1),
		/* Enlarge allocations. */
		new_mp = krealloc(mk->mp,
		sizeof(*mk->mp) +
		sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
		GFP_KERNEL);
		if (!new) {
		kfree(attrs);
		err = -ENOMEM;
		goto fail;
		}
		/* Despite looking like the typical realloc() bug, this is safe.
		* We want the old 'attrs' to be freed either way, and we'll store
		* the new one in the success case. */
		attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
		if (!attrs) {
		err = -ENOMEM;
		goto fail_free_new;
		}

		/* Sysfs wants everything zeroed. */
		memset(new, 0, sizeof(*new));
		memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
		memset(&attrs[num], 0, sizeof(attrs[num]));
		new->grp.name = "parameters";
		new->grp.attrs = attrs;
		if (!new_mp)
		return -ENOMEM;
		mk->mp = new_mp;

		/* Extra pointer for NULL terminator */
		new_attrs = krealloc(mk->mp->grp.attrs,
		sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
		GFP_KERNEL);
		if (!new_attrs)
		return -ENOMEM;
		mk->mp->grp.attrs = new_attrs;

		/* Tack new one on the end. */
		sysfs_attr_init(&new->attrs[num].mattr.attr);
		new->attrs[num].param = kp;
		new->attrs[num].mattr.show = param_attr_show;
		new->attrs[num].mattr.store = param_attr_store;
		new->attrs[num].mattr.attr.name = (char *)name;
		new->attrs[num].mattr.attr.mode = kp->perm;
		new->num = num+1;
		sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
		mk->mp->attrs[mk->mp->num].param = kp;
		mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
		/* Do not allow runtime DAC changes to make param writable. */
		if ((kp->perm & (S_IWUSR \| S_IWGRP \| S_IWOTH)) != 0)
		mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
		mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
		mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
		mk->mp->num++;

		/* Fix up all the pointers, since krealloc can move us */
		for (num = 0; num < new->num; num++)
		new->grp.attrs[num] = &new->attrs[num].mattr.attr;
		new->grp.attrs[num] = NULL;

		mk->mp = new;
		for (i = 0; i < mk->mp->num; i++)
		mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
		mk->mp->grp.attrs[mk->mp->num] = NULL;
		return 0;

		fail_free_new:
		kfree(new);
		fail:
		mk->mp = NULL;
		return err;
		}

		#ifdef CONFIG_MODULES
		static void free_module_param_attrs(struct module_kobject *mk)
		{
		if (mk->mp)
		kfree(mk->mp->grp.attrs);
		kfree(mk->mp);
		mk->mp = NULL;
		@@ -695,8 +688,10 @@ int module_param_sysfs_setup(struct module *mod,
		if (kparam[i].perm == 0)
		continue;
		err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
		if (err)
		if (err) {
		free_module_param_attrs(&mod->mkobj);
		return err;
		}
		params = true;
		}

lib/bug.c

+14 −6

Original line number	Diff line number	Diff line
		@@ -64,16 +64,22 @@ static LIST_HEAD(module_bug_list);
		static const struct bug_entry *module_find_bug(unsigned long bugaddr)
		{
		struct module *mod;
		const struct bug_entry *bug = NULL;

		list_for_each_entry(mod, &module_bug_list, bug_list) {
		const struct bug_entry *bug = mod->bug_table;
		rcu_read_lock();
		list_for_each_entry_rcu(mod, &module_bug_list, bug_list) {
		unsigned i;

		bug = mod->bug_table;
		for (i = 0; i < mod->num_bugs; ++i, ++bug)
		if (bugaddr == bug_addr(bug))
		return bug;
		goto out;
		}
		return NULL;
		bug = NULL;
		out:
		rcu_read_unlock();

		return bug;
		}

		void module_bug_finalize(const Elf_Ehdr hdr, const Elf_Shdr sechdrs,
		@@ -99,13 +105,15 @@ void module_bug_finalize(const Elf_Ehdr hdr, const Elf_Shdr sechdrs,
		* Strictly speaking this should have a spinlock to protect against
		* traversals, but since we only traverse on BUG()s, a spinlock
		* could potentially lead to deadlock and thus be counter-productive.
		* Thus, this uses RCU to safely manipulate the bug list, since BUG
		* must run in non-interruptive state.
		*/
		list_add(&mod->bug_list, &module_bug_list);
		list_add_rcu(&mod->bug_list, &module_bug_list);
		}

		void module_bug_cleanup(struct module *mod)
		{
		list_del(&mod->bug_list);
		list_del_rcu(&mod->bug_list);
		}

		#else

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