Merge branch 'for-6.1-hash-pointer-init' into for-linus

}

early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);

static DEFINE_STATIC_KEY_FALSE(filled_random_ptr_key);

static bool filled_random_ptr_key __read_mostly;

static siphash_key_t ptr_key __read_mostly;

static void fill_ptr_key_workfn(struct work_struct *work);

static DECLARE_DELAYED_WORK(fill_ptr_key_work, fill_ptr_key_workfn);

static void enable_ptr_key_workfn(struct work_struct *work)

static void fill_ptr_key_workfn(struct work_struct *work)

{

	static_branch_enable(&filled_random_ptr_key);

	if (!rng_is_initialized()) {

		queue_delayed_work(system_unbound_wq, &fill_ptr_key_work, HZ  * 2);

		return;

	}

	get_random_bytes(&ptr_key, sizeof(ptr_key));

	/* Pairs with smp_rmb() before reading ptr_key. */

	smp_wmb();

	WRITE_ONCE(filled_random_ptr_key, true);

}

static int __init vsprintf_init_hashval(void)

{

	fill_ptr_key_workfn(NULL);

	return 0;

}

subsys_initcall(vsprintf_init_hashval)

/* Maps a pointer to a 32 bit unique identifier. */

static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)

{

	static siphash_key_t ptr_key __read_mostly;

	unsigned long hashval;

	if (!static_branch_likely(&filled_random_ptr_key)) {

		static bool filled = false;

		static DEFINE_SPINLOCK(filling);

		static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);

		unsigned long flags;

		if (!system_unbound_wq || !rng_is_initialized() ||

		    !spin_trylock_irqsave(&filling, flags))

			return -EAGAIN;

		if (!filled) {

			get_random_bytes(&ptr_key, sizeof(ptr_key));

			queue_work(system_unbound_wq, &enable_ptr_key_work);

			filled = true;

		}

		spin_unlock_irqrestore(&filling, flags);

	}

	if (!READ_ONCE(filled_random_ptr_key))

		return -EBUSY;

	/* Pairs with smp_wmb() after writing ptr_key. */

	smp_rmb();

#ifdef CONFIG_64BIT

	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);