efi: Use a file local lock for efivars (217b27d4) · Commits · 戴 / test

drivers/firmware/efi/vars.c

+47 −36

Original line number	Diff line number	Diff line
		@@ -37,6 +37,14 @@
		/* Private pointer to registered efivars */
		static struct efivars *__efivars;

		/*
		* efivars_lock protects three things:
		* 1) efivarfs_list and efivars_sysfs_list
		* 2) ->ops calls
		* 3) (un)registration of __efivars
		*/
		static DEFINE_SPINLOCK(efivars_lock);

		static bool efivar_wq_enabled = true;
		DECLARE_WORK(efivar_work, NULL);
		EXPORT_SYMBOL_GPL(efivar_work);
		@@ -434,7 +442,7 @@ int efivar_init(int (func)(efi_char16_t , efi_guid_t, unsigned long, void *),
		return -ENOMEM;
		}

		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);

		/*
		* Per EFI spec, the maximum storage allocated for both
		@@ -450,7 +458,7 @@ int efivar_init(int (func)(efi_char16_t , efi_guid_t, unsigned long, void *),
		switch (status) {
		case EFI_SUCCESS:
		if (duplicates)
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);

		variable_name_size = var_name_strnsize(variable_name,
		variable_name_size);
		@@ -477,7 +485,7 @@ int efivar_init(int (func)(efi_char16_t , efi_guid_t, unsigned long, void *),
		}

		if (duplicates)
		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);

		break;
		case EFI_NOT_FOUND:
		@@ -491,7 +499,7 @@ int efivar_init(int (func)(efi_char16_t , efi_guid_t, unsigned long, void *),

		} while (status != EFI_NOT_FOUND);

		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);

		kfree(variable_name);

		@@ -506,9 +514,9 @@ EXPORT_SYMBOL_GPL(efivar_init);
		*/
		void efivar_entry_add(struct efivar_entry entry, struct list_head head)
		{
		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);
		list_add(&entry->list, head);
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		}
		EXPORT_SYMBOL_GPL(efivar_entry_add);

		@@ -518,9 +526,9 @@ EXPORT_SYMBOL_GPL(efivar_entry_add);
		*/
		void efivar_entry_remove(struct efivar_entry *entry)
		{
		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);
		list_del(&entry->list);
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		}
		EXPORT_SYMBOL_GPL(efivar_entry_remove);

		@@ -537,10 +545,10 @@ EXPORT_SYMBOL_GPL(efivar_entry_remove);
		*/
		static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
		{
		lockdep_assert_held(&__efivars->lock);
		lockdep_assert_held(&efivars_lock);

		list_del(&entry->list);
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		}

		/**
		@@ -563,7 +571,7 @@ int __efivar_entry_delete(struct efivar_entry *entry)
		const struct efivar_operations *ops = __efivars->ops;
		efi_status_t status;

		lockdep_assert_held(&__efivars->lock);
		lockdep_assert_held(&efivars_lock);

		status = ops->set_variable(entry->var.VariableName,
		&entry->var.VendorGuid,
		@@ -589,12 +597,12 @@ int efivar_entry_delete(struct efivar_entry *entry)
		const struct efivar_operations *ops = __efivars->ops;
		efi_status_t status;

		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);
		status = ops->set_variable(entry->var.VariableName,
		&entry->var.VendorGuid,
		0, 0, NULL);
		if (!(status == EFI_SUCCESS \|\| status == EFI_NOT_FOUND)) {
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		return efi_status_to_err(status);
		}

		@@ -632,10 +640,10 @@ int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
		efi_char16_t *name = entry->var.VariableName;
		efi_guid_t vendor = entry->var.VendorGuid;

		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);

		if (head && efivar_entry_find(name, vendor, head, false)) {
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		return -EEXIST;
		}

		@@ -644,7 +652,7 @@ int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
		status = ops->set_variable(name, &vendor,
		attributes, size, data);

		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);

		return efi_status_to_err(status);

		@@ -658,7 +666,7 @@ EXPORT_SYMBOL_GPL(efivar_entry_set);
		* from crash/panic handlers.
		*
		* Crucially, this function will not block if it cannot acquire
		* __efivars->lock. Instead, it returns -EBUSY.
		* efivars_lock. Instead, it returns -EBUSY.
		*/
		static int
		efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
		@@ -668,20 +676,20 @@ efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
		unsigned long flags;
		efi_status_t status;

		if (!spin_trylock_irqsave(&__efivars->lock, flags))
		if (!spin_trylock_irqsave(&efivars_lock, flags))
		return -EBUSY;

		status = check_var_size_nonblocking(attributes,
		size + ucs2_strsize(name, 1024));
		if (status != EFI_SUCCESS) {
		spin_unlock_irqrestore(&__efivars->lock, flags);
		spin_unlock_irqrestore(&efivars_lock, flags);
		return -ENOSPC;
		}

		status = ops->set_variable_nonblocking(name, &vendor, attributes,
		size, data);

		spin_unlock_irqrestore(&__efivars->lock, flags);
		spin_unlock_irqrestore(&efivars_lock, flags);
		return efi_status_to_err(status);
		}

		@@ -727,21 +735,21 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
		size, data);

		if (!block) {
		if (!spin_trylock_irqsave(&__efivars->lock, flags))
		if (!spin_trylock_irqsave(&efivars_lock, flags))
		return -EBUSY;
		} else {
		spin_lock_irqsave(&__efivars->lock, flags);
		spin_lock_irqsave(&efivars_lock, flags);
		}

		status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
		if (status != EFI_SUCCESS) {
		spin_unlock_irqrestore(&__efivars->lock, flags);
		spin_unlock_irqrestore(&efivars_lock, flags);
		return -ENOSPC;
		}

		status = ops->set_variable(name, &vendor, attributes, size, data);

		spin_unlock_irqrestore(&__efivars->lock, flags);
		spin_unlock_irqrestore(&efivars_lock, flags);

		return efi_status_to_err(status);
		}
		@@ -771,7 +779,7 @@ struct efivar_entry efivar_entry_find(efi_char16_t name, efi_guid_t guid,
		int strsize1, strsize2;
		bool found = false;

		lockdep_assert_held(&__efivars->lock);
		lockdep_assert_held(&efivars_lock);

		list_for_each_entry_safe(entry, n, head, list) {
		strsize1 = ucs2_strsize(name, 1024);
		@@ -814,10 +822,10 @@ int efivar_entry_size(struct efivar_entry entry, unsigned long size)

		*size = 0;

		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);
		status = ops->get_variable(entry->var.VariableName,
		&entry->var.VendorGuid, NULL, size, NULL);
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);

		if (status != EFI_BUFFER_TOO_SMALL)
		return efi_status_to_err(status);
		@@ -843,7 +851,7 @@ int __efivar_entry_get(struct efivar_entry entry, u32 attributes,
		const struct efivar_operations *ops = __efivars->ops;
		efi_status_t status;

		lockdep_assert_held(&__efivars->lock);
		lockdep_assert_held(&efivars_lock);

		status = ops->get_variable(entry->var.VariableName,
		&entry->var.VendorGuid,
		@@ -866,11 +874,11 @@ int efivar_entry_get(struct efivar_entry entry, u32 attributes,
		const struct efivar_operations *ops = __efivars->ops;
		efi_status_t status;

		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);
		status = ops->get_variable(entry->var.VariableName,
		&entry->var.VendorGuid,
		attributes, size, data);
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);

		return efi_status_to_err(status);
		}
		@@ -917,7 +925,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
		* set_variable call, and removal of the variable from the efivars
		* list (in the case of an authenticated delete).
		*/
		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);

		/*
		* Ensure that the available space hasn't shrunk below the safe level
		@@ -957,7 +965,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
		if (status == EFI_NOT_FOUND)
		efivar_entry_list_del_unlock(entry);
		else
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);

		if (status && status != EFI_BUFFER_TOO_SMALL)
		return efi_status_to_err(status);
		@@ -965,7 +973,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
		return 0;

		out:
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		return err;

		}
		@@ -980,7 +988,7 @@ EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
		*/
		void efivar_entry_iter_begin(void)
		{
		spin_lock_irq(&__efivars->lock);
		spin_lock_irq(&efivars_lock);
		}
		EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);

		@@ -991,7 +999,7 @@ EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
		*/
		void efivar_entry_iter_end(void)
		{
		spin_unlock_irq(&__efivars->lock);
		spin_unlock_irq(&efivars_lock);
		}
		EXPORT_SYMBOL_GPL(efivar_entry_iter_end);

		@@ -1112,11 +1120,12 @@ int efivars_register(struct efivars *efivars,
		const struct efivar_operations *ops,
		struct kobject *kobject)
		{
		spin_lock_init(&efivars->lock);
		spin_lock_irq(&efivars_lock);
		efivars->ops = ops;
		efivars->kobject = kobject;

		__efivars = efivars;
		spin_unlock_irq(&efivars_lock);

		return 0;
		}
		@@ -1133,6 +1142,7 @@ int efivars_unregister(struct efivars *efivars)
		{
		int rv;

		spin_lock_irq(&efivars_lock);
		if (!__efivars) {
		printk(KERN_ERR "efivars not registered\n");
		rv = -EINVAL;
		@@ -1148,6 +1158,7 @@ int efivars_unregister(struct efivars *efivars)

		rv = 0;
		out:
		spin_unlock_irq(&efivars_lock);
		return rv;
		}
		EXPORT_SYMBOL_GPL(efivars_unregister);

include/linux/efi.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -1157,12 +1157,6 @@ struct efivar_operations {
		};

		struct efivars {
		/*
		* ->lock protects two things:
		* 1) efivarfs_list and efivars_sysfs_list
		* 2) ->ops calls
		*/
		spinlock_t lock;
		struct kset *kset;
		struct kobject *kobject;
		const struct efivar_operations *ops;

Admin message