Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 58b022ac authored by PrasannaKumar Muralidharan's avatar PrasannaKumar Muralidharan Committed by Herbert Xu
Browse files

hwrng: core - Allocate memory during module init 



In core rng_buffer and rng_fillbuf is allocated in hwrng_register only
once and it is freed during module exit. This patch moves allocating
rng_buffer and rng_fillbuf from hwrng_register to rng core's init. This
avoids checking whether rng_buffer and rng_fillbuf was allocated from
every hwrng_register call. Also moving them to module init makes it
explicit that it is freed in module exit.

Change in v2:
Fix memory leak when register_miscdev fails.

Signed-off-by: default avatarPrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 378bc4ed

drivers/char/hw_random/core.c

+20 −17
Original line number Diff line number Diff line
@@ -449,22 +449,6 @@ int hwrng_register(struct hwrng *rng) 
		goto out;



	mutex_lock(&rng_mutex);



	/* kmalloc makes this safe for virt_to_page() in virtio_rng.c */

	err = -ENOMEM;

	if (!rng_buffer) {

		rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL);

		if (!rng_buffer)

			goto out_unlock;

	}

	if (!rng_fillbuf) {

		rng_fillbuf = kmalloc(rng_buffer_size(), GFP_KERNEL);

		if (!rng_fillbuf) {

			kfree(rng_buffer);

			goto out_unlock;

		}

	}



	/* Must not register two RNGs with the same name. */

	err = -EEXIST;

	list_for_each_entry(tmp, &rng_list, list) {
@@ -573,7 +557,26 @@ EXPORT_SYMBOL_GPL(devm_hwrng_unregister); 


static int __init hwrng_modinit(void)

{

	return register_miscdev();

	int ret = -ENOMEM;



	/* kmalloc makes this safe for virt_to_page() in virtio_rng.c */

	rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL);

	if (!rng_buffer)

		return -ENOMEM;



	rng_fillbuf = kmalloc(rng_buffer_size(), GFP_KERNEL);

	if (!rng_fillbuf) {

		kfree(rng_buffer);

		return -ENOMEM;

	}



	ret = register_miscdev();

	if (ret) {

		kfree(rng_fillbuf);

		kfree(rng_buffer);

	}



	return ret;

}



static void __exit hwrng_modexit(void)