Hi,
On 26/03/2020 15:24, Alexandru Elisei wrote:
> Don't ignore an error in the bus specific initialization function in
> virtio_init; don't ignore the result of virtio_init; and don't return 0
> in virtio_blk__init and virtio_scsi__init when we encounter an error.
> Hopefully this will save some developer's time debugging faulty virtio
> devices in a guest.
>
> To take advantage of the cleanup function virtio_blk__exit, we have
> moved appending the new device to the list before the call to
> virtio_init.
>
> To safeguard against this in the future, virtio_init has been annoted
> with the compiler attribute warn_unused_result.
This is a good idea, but actually triggers an unrelated, long standing
bug in vesa.c (on x86):
hw/vesa.c: In function ‘vesa__init’:
hw/vesa.c:77:3: error: ignoring return value of ‘ERR_PTR’, declared with
attribute warn_unused_result [-Werror=unused-result]
ERR_PTR(-errno);
^
cc1: all warnings being treated as errors
So could you add the missing "return" statement in that line, to fix
that bug?
I see that this gets rectified two patches later, but for the sake of
bisect-ability it would be good to keep this compilable all the way through.
>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> ---
> include/kvm/kvm.h | 1 +
> include/kvm/virtio.h | 7 ++++---
> include/linux/compiler.h | 2 +-
> virtio/9p.c | 9 ++++++---
> virtio/balloon.c | 10 +++++++---
> virtio/blk.c | 14 +++++++++-----
> virtio/console.c | 11 ++++++++---
> virtio/core.c | 9 +++++----
> virtio/net.c | 32 ++++++++++++++++++--------------
> virtio/scsi.c | 14 +++++++++-----
> 10 files changed, 68 insertions(+), 41 deletions(-)
>
> diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
> index 7a738183d67a..c6dc6ef72d11 100644
> --- a/include/kvm/kvm.h
> +++ b/include/kvm/kvm.h
> @@ -8,6 +8,7 @@
>
> #include <stdbool.h>
> #include <linux/types.h>
> +#include <linux/compiler.h>
> #include <time.h>
> #include <signal.h>
> #include <sys/prctl.h>
> diff --git a/include/kvm/virtio.h b/include/kvm/virtio.h
> index 19b913732cd5..3a311f54f2a5 100644
> --- a/include/kvm/virtio.h
> +++ b/include/kvm/virtio.h
> @@ -7,6 +7,7 @@
> #include <linux/virtio_pci.h>
>
> #include <linux/types.h>
> +#include <linux/compiler.h>
> #include <linux/virtio_config.h>
> #include <sys/uio.h>
>
> @@ -204,9 +205,9 @@ struct virtio_ops {
> int (*reset)(struct kvm *kvm, struct virtio_device *vdev);
> };
>
> -int virtio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
> - struct virtio_ops *ops, enum virtio_trans trans,
> - int device_id, int subsys_id, int class);
> +int __must_check virtio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
> + struct virtio_ops *ops, enum virtio_trans trans,
> + int device_id, int subsys_id, int class);
> int virtio_compat_add_message(const char *device, const char *config);
> const char* virtio_trans_name(enum virtio_trans trans);
>
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index 898420b81aec..a662ba0a5c68 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -14,7 +14,7 @@
> #define __packed __attribute__((packed))
> #define __iomem
> #define __force
> -#define __must_check
> +#define __must_check __attribute__((warn_unused_result))
> #define unlikely
>
> #endif
> diff --git a/virtio/9p.c b/virtio/9p.c
> index ac70dbc31207..b78f2b3f0e09 100644
> --- a/virtio/9p.c
> +++ b/virtio/9p.c
> @@ -1551,11 +1551,14 @@ int virtio_9p_img_name_parser(const struct option *opt, const char *arg, int uns
> int virtio_9p__init(struct kvm *kvm)
> {
> struct p9_dev *p9dev;
> + int r;
>
> list_for_each_entry(p9dev, &devs, list) {
> - virtio_init(kvm, p9dev, &p9dev->vdev, &p9_dev_virtio_ops,
> - VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_9P,
> - VIRTIO_ID_9P, PCI_CLASS_9P);
> + r = virtio_init(kvm, p9dev, &p9dev->vdev, &p9_dev_virtio_ops,
> + VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_9P,
> + VIRTIO_ID_9P, PCI_CLASS_9P);
> + if (r < 0)
> + return r;
> }
>
> return 0;
> diff --git a/virtio/balloon.c b/virtio/balloon.c
> index 0bd16703dfee..8e8803fed607 100644
> --- a/virtio/balloon.c
> +++ b/virtio/balloon.c
> @@ -264,6 +264,8 @@ struct virtio_ops bln_dev_virtio_ops = {
>
> int virtio_bln__init(struct kvm *kvm)
> {
> + int r;
> +
> if (!kvm->cfg.balloon)
> return 0;
>
> @@ -273,9 +275,11 @@ int virtio_bln__init(struct kvm *kvm)
> bdev.stat_waitfd = eventfd(0, 0);
> memset(&bdev.config, 0, sizeof(struct virtio_balloon_config));
>
> - virtio_init(kvm, &bdev, &bdev.vdev, &bln_dev_virtio_ops,
> - VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_BLN,
> - VIRTIO_ID_BALLOON, PCI_CLASS_BLN);
> + r = virtio_init(kvm, &bdev, &bdev.vdev, &bln_dev_virtio_ops,
> + VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_BLN,
> + VIRTIO_ID_BALLOON, PCI_CLASS_BLN);
> + if (r < 0)
> + return r;
>
> if (compat_id == -1)
> compat_id = virtio_compat_add_message("virtio-balloon", "CONFIG_VIRTIO_BALLOON");
> diff --git a/virtio/blk.c b/virtio/blk.c
> index f267be1563dc..4d02d101af81 100644
> --- a/virtio/blk.c
> +++ b/virtio/blk.c
> @@ -306,6 +306,7 @@ static struct virtio_ops blk_dev_virtio_ops = {
> static int virtio_blk__init_one(struct kvm *kvm, struct disk_image *disk)
> {
> struct blk_dev *bdev;
> + int r;
>
> if (!disk)
> return -EINVAL;
> @@ -323,12 +324,14 @@ static int virtio_blk__init_one(struct kvm *kvm, struct disk_image *disk)
> .kvm = kvm,
> };
>
> - virtio_init(kvm, bdev, &bdev->vdev, &blk_dev_virtio_ops,
> - VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_BLK,
> - VIRTIO_ID_BLOCK, PCI_CLASS_BLK);
> -
> list_add_tail(&bdev->list, &bdevs);
>
> + r = virtio_init(kvm, bdev, &bdev->vdev, &blk_dev_virtio_ops,
> + VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_BLK,
> + VIRTIO_ID_BLOCK, PCI_CLASS_BLK);
> + if (r < 0)
> + return r;
> +
> disk_image__set_callback(bdev->disk, virtio_blk_complete);
>
> if (compat_id == -1)
> @@ -359,7 +362,8 @@ int virtio_blk__init(struct kvm *kvm)
>
> return 0;
> cleanup:
> - return virtio_blk__exit(kvm);
> + virtio_blk__exit(kvm);
> + return r;
> }
> virtio_dev_init(virtio_blk__init);
>
> diff --git a/virtio/console.c b/virtio/console.c
> index f1be02549222..e0b98df37965 100644
> --- a/virtio/console.c
> +++ b/virtio/console.c
> @@ -230,12 +230,17 @@ static struct virtio_ops con_dev_virtio_ops = {
>
> int virtio_console__init(struct kvm *kvm)
> {
> + int r;
> +
> if (kvm->cfg.active_console != CONSOLE_VIRTIO)
> return 0;
>
> - virtio_init(kvm, &cdev, &cdev.vdev, &con_dev_virtio_ops,
> - VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_CONSOLE,
> - VIRTIO_ID_CONSOLE, PCI_CLASS_CONSOLE);
> + r = virtio_init(kvm, &cdev, &cdev.vdev, &con_dev_virtio_ops,
> + VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_CONSOLE,
> + VIRTIO_ID_CONSOLE, PCI_CLASS_CONSOLE);
> + if (r < 0)
> + return r;
> +
> if (compat_id == -1)
> compat_id = virtio_compat_add_message("virtio-console", "CONFIG_VIRTIO_CONSOLE");
>
> diff --git a/virtio/core.c b/virtio/core.c
> index e10ec362e1ea..f5b3c07fc100 100644
> --- a/virtio/core.c
> +++ b/virtio/core.c
> @@ -259,6 +259,7 @@ int virtio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
> int device_id, int subsys_id, int class)
> {
> void *virtio;
> + int r;
>
> switch (trans) {
> case VIRTIO_PCI:
> @@ -272,7 +273,7 @@ int virtio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
> vdev->ops->init = virtio_pci__init;
> vdev->ops->exit = virtio_pci__exit;
> vdev->ops->reset = virtio_pci__reset;
> - vdev->ops->init(kvm, dev, vdev, device_id, subsys_id, class);
> + r = vdev->ops->init(kvm, dev, vdev, device_id, subsys_id, class);
> break;
> case VIRTIO_MMIO:
> virtio = calloc(sizeof(struct virtio_mmio), 1);
> @@ -285,13 +286,13 @@ int virtio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
> vdev->ops->init = virtio_mmio_init;
> vdev->ops->exit = virtio_mmio_exit;
> vdev->ops->reset = virtio_mmio_reset;
> - vdev->ops->init(kvm, dev, vdev, device_id, subsys_id, class);
> + r = vdev->ops->init(kvm, dev, vdev, device_id, subsys_id, class);
> break;
> default:
> - return -1;
> + r = -1;
> };
>
> - return 0;
> + return r;
> }
>
> int virtio_compat_add_message(const char *device, const char *config)
> diff --git a/virtio/net.c b/virtio/net.c
> index 091406912a24..425c13ba1136 100644
> --- a/virtio/net.c
> +++ b/virtio/net.c
> @@ -910,7 +910,7 @@ done:
>
> static int virtio_net__init_one(struct virtio_net_params *params)
> {
> - int i, err;
> + int i, r;
> struct net_dev *ndev;
> struct virtio_ops *ops;
> enum virtio_trans trans = VIRTIO_DEFAULT_TRANS(params->kvm);
> @@ -920,10 +920,8 @@ static int virtio_net__init_one(struct virtio_net_params *params)
> return -ENOMEM;
>
> ops = malloc(sizeof(*ops));
> - if (ops == NULL) {
> - err = -ENOMEM;
> - goto err_free_ndev;
> - }
> + if (ops == NULL)
> + return -ENOMEM;
>
> list_add_tail(&ndev->list, &ndevs);
As mentioned in the reply to the v2 version, I think this is still
leaking memory here.
The rest looks fine.
Cheers,
Andre
>
> @@ -969,8 +967,10 @@ static int virtio_net__init_one(struct virtio_net_params *params)
> virtio_trans_name(trans));
> }
>
> - virtio_init(params->kvm, ndev, &ndev->vdev, ops, trans,
> - PCI_DEVICE_ID_VIRTIO_NET, VIRTIO_ID_NET, PCI_CLASS_NET);
> + r = virtio_init(params->kvm, ndev, &ndev->vdev, ops, trans,
> + PCI_DEVICE_ID_VIRTIO_NET, VIRTIO_ID_NET, PCI_CLASS_NET);
> + if (r < 0)
> + return r;
>
> if (params->vhost)
> virtio_net__vhost_init(params->kvm, ndev);
> @@ -979,19 +979,17 @@ static int virtio_net__init_one(struct virtio_net_params *params)
> compat_id = virtio_compat_add_message("virtio-net", "CONFIG_VIRTIO_NET");
>
> return 0;
> -
> -err_free_ndev:
> - free(ndev);
> - return err;
> }
>
> int virtio_net__init(struct kvm *kvm)
> {
> - int i;
> + int i, r;
>
> for (i = 0; i < kvm->cfg.num_net_devices; i++) {
> kvm->cfg.net_params[i].kvm = kvm;
> - virtio_net__init_one(&kvm->cfg.net_params[i]);
> + r = virtio_net__init_one(&kvm->cfg.net_params[i]);
> + if (r < 0)
> + goto cleanup;
> }
>
> if (kvm->cfg.num_net_devices == 0 && kvm->cfg.no_net == 0) {
> @@ -1007,10 +1005,16 @@ int virtio_net__init(struct kvm *kvm)
> str_to_mac(kvm->cfg.guest_mac, net_params.guest_mac);
> str_to_mac(kvm->cfg.host_mac, net_params.host_mac);
>
> - virtio_net__init_one(&net_params);
> + r = virtio_net__init_one(&net_params);
> + if (r < 0)
> + goto cleanup;
> }
>
> return 0;
> +
> +cleanup:
> + virtio_net__exit(kvm);
> + return r;
> }
> virtio_dev_init(virtio_net__init);
>
> diff --git a/virtio/scsi.c b/virtio/scsi.c
> index 1ec78fe0945a..16a86cb7e0e6 100644
> --- a/virtio/scsi.c
> +++ b/virtio/scsi.c
> @@ -234,6 +234,7 @@ static void virtio_scsi_vhost_init(struct kvm *kvm, struct scsi_dev *sdev)
> static int virtio_scsi_init_one(struct kvm *kvm, struct disk_image *disk)
> {
> struct scsi_dev *sdev;
> + int r;
>
> if (!disk)
> return -EINVAL;
> @@ -260,12 +261,14 @@ static int virtio_scsi_init_one(struct kvm *kvm, struct disk_image *disk)
> strlcpy((char *)&sdev->target.vhost_wwpn, disk->wwpn, sizeof(sdev->target.vhost_wwpn));
> sdev->target.vhost_tpgt = strtol(disk->tpgt, NULL, 0);
>
> - virtio_init(kvm, sdev, &sdev->vdev, &scsi_dev_virtio_ops,
> - VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_SCSI,
> - VIRTIO_ID_SCSI, PCI_CLASS_BLK);
> -
> list_add_tail(&sdev->list, &sdevs);
>
> + r = virtio_init(kvm, sdev, &sdev->vdev, &scsi_dev_virtio_ops,
> + VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_SCSI,
> + VIRTIO_ID_SCSI, PCI_CLASS_BLK);
> + if (r < 0)
> + return r;
> +
> virtio_scsi_vhost_init(kvm, sdev);
>
> if (compat_id == -1)
> @@ -302,7 +305,8 @@ int virtio_scsi_init(struct kvm *kvm)
>
> return 0;
> cleanup:
> - return virtio_scsi_exit(kvm);
> + virtio_scsi_exit(kvm);
> + return r;
> }
> virtio_dev_init(virtio_scsi_init);
>
>
