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

Commit a17597d3 authored by Sasha Levin's avatar Sasha Levin Committed by Rusty Russell
Browse files

virtio-rng: fixes for device registration/unregistration 



There are several fixes in this patch (mostly because it's hard
splitting them up):

 - Revert the name field in struct hwrng back to 'const'. Also, don't
do an extra kmalloc for the name - just wasteful.
 - Deal with allocation failures properly.
 - Use IDA to allocate device number instead of brute forcing one.

Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent e5d23a8c

drivers/char/hw_random/virtio-rng.c

+23 −18
Original line number Original line Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/virtio_rng.h>

#include <linux/virtio_rng.h>

#include <linux/module.h>

#include <linux/module.h>





static DEFINE_IDA(rng_index_ida);





struct virtrng_info {

struct virtrng_info {

	struct virtio_device *vdev;

	struct virtio_device *vdev;
@@ -33,6 +34,8 @@ struct virtrng_info { 
	unsigned int data_avail;

	unsigned int data_avail;

	struct completion have_data;

	struct completion have_data;

	bool busy;

	bool busy;

	char name[25];

	int index;

};

};





static void random_recv_done(struct virtqueue *vq)

static void random_recv_done(struct virtqueue *vq)
@@ -92,41 +95,45 @@ static void virtio_cleanup(struct hwrng *rng) 




static int probe_common(struct virtio_device *vdev)

static int probe_common(struct virtio_device *vdev)

{

{

	int err, i;

	int err, index;

	struct virtrng_info *vi = NULL;

	struct virtrng_info *vi = NULL;





	vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);

	vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);

	vi->hwrng.name = kmalloc(40, GFP_KERNEL);

	if (!vi)

		return -ENOMEM;



	vi->index = index = ida_simple_get(&rng_index_ida, 0, 0, GFP_KERNEL);

	if (index < 0) {

		kfree(vi);

		return index;

	}

	sprintf(vi->name, "virtio_rng.%d", index);

	init_completion(&vi->have_data);

	init_completion(&vi->have_data);





	vi->hwrng.read = virtio_read;

	vi->hwrng = (struct hwrng) {

	vi->hwrng.cleanup = virtio_cleanup;

		.read = virtio_read,

	vi->hwrng.priv = (unsigned long)vi;

		.cleanup = virtio_cleanup,

		.priv = (unsigned long)vi,

		.name = vi->name,

	};

	vdev->priv = vi;

	vdev->priv = vi;





	/* We expect a single virtqueue. */

	/* We expect a single virtqueue. */

	vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");

	vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");

	if (IS_ERR(vi->vq)) {

	if (IS_ERR(vi->vq)) {

		err = PTR_ERR(vi->vq);

		err = PTR_ERR(vi->vq);

		kfree(vi->hwrng.name);

		vi->vq = NULL;

		vi->vq = NULL;

		kfree(vi);

		kfree(vi);

		vi = NULL;

		ida_simple_remove(&rng_index_ida, index);

		return err;

		return err;

	}

	}





	i = 0;

	do {

		sprintf(vi->hwrng.name, "virtio_rng.%d", i++);

	err = hwrng_register(&vi->hwrng);

	err = hwrng_register(&vi->hwrng);

	} while (err == -EEXIST);



	if (err) {

	if (err) {

		vdev->config->del_vqs(vdev);

		vdev->config->del_vqs(vdev);

		kfree(vi->hwrng.name);

		vi->vq = NULL;

		vi->vq = NULL;

		kfree(vi);

		kfree(vi);

		vi = NULL;

		ida_simple_remove(&rng_index_ida, index);

		return err;

		return err;

	}

	}
@@ -140,10 +147,8 @@ static void remove_common(struct virtio_device *vdev) 
	vi->busy = false;

	vi->busy = false;

	hwrng_unregister(&vi->hwrng);

	hwrng_unregister(&vi->hwrng);

	vdev->config->del_vqs(vdev);

	vdev->config->del_vqs(vdev);

	kfree(vi->hwrng.name);

	ida_simple_remove(&rng_index_ida, vi->index);

	vi->vq = NULL;

	kfree(vi);

	kfree(vi);

	vi = NULL;

}

}





static int virtrng_probe(struct virtio_device *vdev)

static int virtrng_probe(struct virtio_device *vdev)

include/linux/hw_random.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -31,7 +31,7 @@ 
 * @priv:		Private data, for use by the RNG driver.

 * @priv:		Private data, for use by the RNG driver.

 */

 */

struct hwrng {

struct hwrng {

	char *name;

	const char *name;

	int (*init)(struct hwrng *rng);

	int (*init)(struct hwrng *rng);

	void (*cleanup)(struct hwrng *rng);

	void (*cleanup)(struct hwrng *rng);

	int (*data_present)(struct hwrng *rng, int wait);

	int (*data_present)(struct hwrng *rng, int wait);