On Wed Sep 25 19, Joerg Roedel wrote:
From: Joerg Roedel <jroe...@suse.de>Make sure that attaching a detaching a device can't race against each other and protect the iommu_dev_data with a spin_lock in these code paths. Fixes: 92d420ec028d ("iommu/amd: Relax locking in dma_ops path") Signed-off-by: Joerg Roedel <jroe...@suse.de> --- drivers/iommu/amd_iommu.c | 9 +++++++++ drivers/iommu/amd_iommu_types.h | 3 +++ 2 files changed, 12 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 459247c32dc0..bac4e20a5919 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -201,6 +201,7 @@ static struct iommu_dev_data *alloc_dev_data(u16 devid) if (!dev_data) return NULL; + spin_lock_init(&dev_data->lock); dev_data->devid = devid; ratelimit_default_init(&dev_data->rs); @@ -2157,6 +2158,8 @@ static int attach_device(struct device *dev, dev_data = get_dev_data(dev); + spin_lock(&dev_data->lock); + ret = -EBUSY; if (dev_data->domain != NULL) goto out; @@ -2199,6 +2202,8 @@ static int attach_device(struct device *dev, domain_flush_complete(domain); out: + spin_unlock(&dev_data->lock); + spin_unlock_irqrestore(&domain->lock, flags); return ret; @@ -2218,6 +2223,8 @@ static void detach_device(struct device *dev) spin_lock_irqsave(&domain->lock, flags); + spin_lock(&dev_data->lock); + /* * First check if the device is still attached. It might already * be detached from its domain because the generic @@ -2240,6 +2247,8 @@ static void detach_device(struct device *dev) dev_data->ats.enabled = false; out: + spin_unlock(&dev_data->lock); + spin_unlock_irqrestore(&domain->lock, flags); } diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index 0186501ab971..c9c1612d52e0 100644 --- a/drivers/iommu/amd_iommu_types.h +++ b/drivers/iommu/amd_iommu_types.h @@ -633,6 +633,9 @@ struct devid_map { * This struct contains device specific data for the IOMMU */ struct iommu_dev_data { + /*Protect against attach/detach races */ + spinlock_t lock; + struct list_head list; /* For domain->dev_list */ struct llist_node dev_data_list; /* For global dev_data_list */ struct protection_domain *domain; /* Domain the device is bound to */ -- 2.17.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Reviewed-by: Jerry Snitselaar <jsnit...@redhat.com> _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
