search for: module_put

...nternal interface between > modules. The user is interacting with filesystem objects from the vfio > module and the module reference we're trying to acquire here is to the > vfio-mdev module. Thanks, > > Alex I think the latent bug refers not to module get per se, but to the module_put tied to it. E.g.: static void vfio_mdev_release(void *device_data) { struct mdev_device *mdev = device_data; struct mdev_parent *parent = mdev->parent; if (likely(parent->ops->release)) parent->ops->release(mdev); module_put(THIS_M...

...nternal interface between > modules. The user is interacting with filesystem objects from the vfio > module and the module reference we're trying to acquire here is to the > vfio-mdev module. Thanks, > > Alex I think the latent bug refers not to module get per se, but to the module_put tied to it. E.g.: static void vfio_mdev_release(void *device_data) { struct mdev_device *mdev = device_data; struct mdev_parent *parent = mdev->parent; if (likely(parent->ops->release)) parent->ops->release(mdev); module_put(THIS_M...

...he user is interacting with filesystem objects from the vfio > > module and the module reference we're trying to acquire here is to the > > vfio-mdev module. Thanks, > > > > Alex > > > I think the latent bug refers not to module get per se, > but to the module_put tied to it. E.g.: > > static void vfio_mdev_release(void *device_data) > { > struct mdev_device *mdev = device_data; > struct mdev_parent *parent = mdev->parent; > > if (likely(parent->ops->release)) > parent->ops->r...

...ioctl work. I see. Thanks! IIUC, you mean we can provide a very tiny VFIO device driver in drivers/vhost/mdev.c, e.g.: static int vfio_vhost_mdev_open(void *device_data) { if (!try_module_get(THIS_MODULE)) return -ENODEV; return 0; } static void vfio_vhost_mdev_release(void *device_data) { module_put(THIS_MODULE); } static const struct vfio_device_ops vfio_vhost_mdev_dev_ops = { .name = "vfio-vhost-mdev", .open = vfio_vhost_mdev_open, .release = vfio_vhost_mdev_release, }; static int vhost_mdev_probe(struct device *dev) { struct mdev_device *mdev = to_mdev_device(dev); ... C...

...ioctl work. I see. Thanks! IIUC, you mean we can provide a very tiny VFIO device driver in drivers/vhost/mdev.c, e.g.: static int vfio_vhost_mdev_open(void *device_data) { if (!try_module_get(THIS_MODULE)) return -ENODEV; return 0; } static void vfio_vhost_mdev_release(void *device_data) { module_put(THIS_MODULE); } static const struct vfio_device_ops vfio_vhost_mdev_dev_ops = { .name = "vfio-vhost-mdev", .open = vfio_vhost_mdev_open, .release = vfio_vhost_mdev_release, }; static int vhost_mdev_probe(struct device *dev) { struct mdev_device *mdev = to_mdev_device(dev); ... C...

...ops *ops = dev->bus->iommu_ops; @@ -191,10 +221,17 @@ int iommu_probe_device(struct device *dev) goto err_free_dev_param; } - ret = ops->add_device(dev); + if (ops->probe_device) + ret = __iommu_probe_device(dev); + else + ret = ops->add_device(dev); + if (ret) goto err_module_put; + if (ops->probe_finalize) + ops->probe_finalize(dev); + return 0; err_module_put: @@ -204,17 +241,31 @@ int iommu_probe_device(struct device *dev) return ret; } +static void __iommu_release_device(struct device *dev) +{ + const struct iommu_ops *ops = dev->bus->iommu_ops;...

...f (!ops) - return -EINVAL; - - if (!dev_iommu_get(dev)) - return -ENOMEM; - - if (!try_module_get(ops->owner)) { - ret = -EINVAL; - goto err_free_dev_param; - } - - if (ops->probe_device) - return __iommu_probe_device_helper(dev); - - ret = ops->add_device(dev); - if (ret) - goto err_module_put; - - group = iommu_group_get(dev); - iommu_create_device_direct_mappings(group, dev); - iommu_group_put(group); - - if (ops->probe_finalize) - ops->probe_finalize(dev); - return 0; - -err_module_put: - module_put(ops->owner); -err_free_dev_param: - dev_iommu_free(dev); - return ret; -}...

...int ret; > > - if (unlikely(!parent->ops->open)) > + if (unlikely(!ops->open)) > return -EINVAL; > > if (!try_module_get(THIS_MODULE)) > return -ENODEV; > > - ret = parent->ops->open(mdev); > + ret = ops->open(mdev); > if (ret) > module_put(THIS_MODULE); > > @@ -44,9 +45,10 @@ static void vfio_mdev_release(void *device_data) > { > struct mdev_device *mdev = device_data; > struct mdev_parent *parent = mdev->parent; > + const struct vfio_mdev_parent_ops *ops = parent->ops- > >device_ops; > > -...

...int ret; > > - if (unlikely(!parent->ops->open)) > + if (unlikely(!ops->open)) > return -EINVAL; > > if (!try_module_get(THIS_MODULE)) > return -ENODEV; > > - ret = parent->ops->open(mdev); > + ret = ops->open(mdev); > if (ret) > module_put(THIS_MODULE); > > @@ -44,9 +45,10 @@ static void vfio_mdev_release(void *device_data) > { > struct mdev_device *mdev = device_data; > struct mdev_parent *parent = mdev->parent; > + const struct vfio_mdev_parent_ops *ops = parent->ops- > >device_ops; > > -...

...*slot, type *value) \ { \ struct hotplug_slot_ops *ops = slot->ops; \ int retval = 0; \ - if (try_module_get(ops->owner)) { \ - if (ops->get_##name) \ - retval = ops->get_##name(slot, value); \ - else \ - *value = slot->info->name; \ - module_put(ops->owner); \ - } \ + if (!try_module_get(ops->owner)) \ + return -ENODEV; \ + if (ops->get_##name) \ + retval = ops->get_##name(slot, value); \ + else \ + *value = slot->info->name; \ + module_put(ops->owner); \ return retval;...

...*slot, type *value) \ { \ struct hotplug_slot_ops *ops = slot->ops; \ int retval = 0; \ - if (try_module_get(ops->owner)) { \ - if (ops->get_##name) \ - retval = ops->get_##name(slot, value); \ - else \ - *value = slot->info->name; \ - module_put(ops->owner); \ - } \ + if (!try_module_get(ops->owner)) \ + return -ENODEV; \ + if (ops->get_##name) \ + retval = ops->get_##name(slot, value); \ + else \ + *value = slot->info->name; \ + module_put(ops->owner); \ return retval;...

...*slot, type *value) \ { \ struct hotplug_slot_ops *ops = slot->ops; \ int retval = 0; \ - if (try_module_get(ops->owner)) { \ - if (ops->get_##name) \ - retval = ops->get_##name(slot, value); \ - else \ - *value = slot->info->name; \ - module_put(ops->owner); \ - } \ + if (!try_module_get(ops->owner)) \ + return -ENODEV; \ + if (ops->get_##name) \ + retval = ops->get_##name(slot, value); \ + else \ + *value = slot->info->name; \ + module_put(ops->owner); \ return retval;...

...} + + dev = &m->dev; + for (i = 0; i < nvqs; i++) { + vqs[i] = &m->vqs[i]; + vqs[i]->handle_kick = handle_vq_kick; + } + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); + m->opened = true; + mutex_unlock(&m->mutex); + + return 0; + +err: + mutex_unlock(&m->mutex); + module_put(THIS_MODULE); + return r; +} + +static void vhost_mdev_release(void *device_data) +{ + struct vhost_mdev *m = device_data; + + mutex_lock(&m->mutex); + vhost_mdev_reset(m); + vhost_dev_stop(&m->dev); + vhost_dev_cleanup(&m->dev); + + kfree(m->dev.vqs); + m->opened = false...

...} + + dev = &m->dev; + for (i = 0; i < nvqs; i++) { + vqs[i] = &m->vqs[i]; + vqs[i]->handle_kick = handle_vq_kick; + } + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); + m->opened = true; + mutex_unlock(&m->mutex); + + return 0; + +err: + mutex_unlock(&m->mutex); + module_put(THIS_MODULE); + return r; +} + +static void vhost_mdev_release(void *device_data) +{ + struct vhost_mdev *m = device_data; + + mutex_lock(&m->mutex); + vhost_mdev_reset(m); + vhost_dev_stop(&m->dev); + vhost_dev_cleanup(&m->dev); + + kfree(m->dev.vqs); + m->opened = false...

...v.c, e.g.: > > > > static int vfio_vhost_mdev_open(void *device_data) > > { > > if (!try_module_get(THIS_MODULE)) > > return -ENODEV; > > return 0; > > } > > > > static void vfio_vhost_mdev_release(void *device_data) > > { > > module_put(THIS_MODULE); > > } > > > > static const struct vfio_device_ops vfio_vhost_mdev_dev_ops = { > > .name = "vfio-vhost-mdev", > > .open = vfio_vhost_mdev_open, > > .release = vfio_vhost_mdev_release, > > }; > > > > static int vhost...

...r of uses of try_module_get(THIS_MODULE) in the kernel source but most if not all of them are latent bugs that should be cleaned up. > > > > > - ret = parent->ops->open(mdev); > > > + ret = ops->open(mdev); > > > if (ret) > > > module_put(THIS_MODULE); > > > > > > @@ -43,10 +44,10 @@ static int vfio_mdev_open(void *device_data) > > > static void vfio_mdev_release(void *device_data) > > > { > > > struct mdev_device *mdev = device_data; > > > - struct mdev_parent *parent =...

...r of uses of try_module_get(THIS_MODULE) in the kernel source but most if not all of them are latent bugs that should be cleaned up. > > > > > - ret = parent->ops->open(mdev); > > > + ret = ops->open(mdev); > > > if (ret) > > > module_put(THIS_MODULE); > > > > > > @@ -43,10 +44,10 @@ static int vfio_mdev_open(void *device_data) > > > static void vfio_mdev_release(void *device_data) > > > { > > > struct mdev_device *mdev = device_data; > > > - struct mdev_parent *parent =...

...to include below vhost header. */ #include "../../vhost/vhost.h" static int vfio_vhost_mdev_open(void *device_data) { if (!try_module_get(THIS_MODULE)) return -ENODEV; /* ... */ vhost_dev_init(...); return 0; } static void vfio_vhost_mdev_release(void *device_data) { /* ... */ module_put(THIS_MODULE); } static long vfio_vhost_mdev_unlocked_ioctl(void *device_data, unsigned int cmd, unsigned long arg) { struct mdev_device *mdev = device_data; struct mdev_parent *parent = mdev->parent; /* * Use vhost ioctls. * * We will have a different parent_ops design. * An...

...to include below vhost header. */ #include "../../vhost/vhost.h" static int vfio_vhost_mdev_open(void *device_data) { if (!try_module_get(THIS_MODULE)) return -ENODEV; /* ... */ vhost_dev_init(...); return 0; } static void vfio_vhost_mdev_release(void *device_data) { /* ... */ module_put(THIS_MODULE); } static long vfio_vhost_mdev_unlocked_ioctl(void *device_data, unsigned int cmd, unsigned long arg) { struct mdev_device *mdev = device_data; struct mdev_parent *parent = mdev->parent; /* * Use vhost ioctls. * * We will have a different parent_ops design. * An...

...{ > + vqs[i] = &m->vqs[i]; > + vqs[i]->handle_kick = handle_vq_kick; > + } > + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); > + m->opened = true; > + mutex_unlock(&m->mutex); > + > + return 0; > + > +err: > + mutex_unlock(&m->mutex); > + module_put(THIS_MODULE); > + return r; > +} > + > +static void vhost_mdev_release(void *device_data) > +{ > + struct vhost_mdev *m = device_data; > + > + mutex_lock(&m->mutex); > + vhost_mdev_reset(m); > + vhost_dev_stop(&m->dev); > + vhost_dev_cleanup(&m-&gt...