lkml.org 
[lkml]   [2023]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 3/7] iommu: Validate that devices match domains
Date
Before we can allow drivers to coexist, we need to make sure that one
driver's domain ops can't misinterpret another driver's dev_iommu_priv
data. To that end, add a token to the domain so we can remember how it
was allocated - for now this may as well be the device ops, since they
still correlate 1:1 with drivers. We can trust ourselves for internal
default domain attachment, so add the check where it covers both the
external attach interfaces.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/iommu/iommu.c | 13 +++++++++----
include/linux/iommu.h | 1 +
2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 2f29ee9dea64..f4cc91227b22 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2000,26 +2000,28 @@ EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
static struct iommu_domain *__iommu_domain_alloc(const struct bus_type *bus,
unsigned type)
{
+ const struct iommu_ops *ops = bus ? bus->iommu_ops : NULL;
struct iommu_domain *domain;
unsigned int alloc_type = type & IOMMU_DOMAIN_ALLOC_FLAGS;

- if (bus == NULL || bus->iommu_ops == NULL)
+ if (!ops)
return NULL;

- domain = bus->iommu_ops->domain_alloc(alloc_type);
+ domain = ops->domain_alloc(alloc_type);
if (!domain)
return NULL;

domain->type = type;
+ domain->owner = ops;
/*
* If not already set, assume all sizes by default; the driver
* may override this later
*/
if (!domain->pgsize_bitmap)
- domain->pgsize_bitmap = bus->iommu_ops->pgsize_bitmap;
+ domain->pgsize_bitmap = ops->pgsize_bitmap;

if (!domain->ops)
- domain->ops = bus->iommu_ops->default_domain_ops;
+ domain->ops = ops->default_domain_ops;

if (iommu_is_dma_domain(domain) && iommu_get_dma_cookie(domain)) {
iommu_domain_free(domain);
@@ -2176,6 +2178,9 @@ static int __iommu_attach_group(struct iommu_domain *domain,
group->domain != group->blocking_domain)
return -EBUSY;

+ if (dev_iommu_ops(iommu_group_first_dev(group)) != domain->owner)
+ return -EINVAL;
+
return __iommu_group_set_domain(group, domain);
}

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index a249e10c8e9f..75ffcac199e3 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -95,6 +95,7 @@ struct iommu_domain_geometry {
struct iommu_domain {
unsigned type;
const struct iommu_domain_ops *ops;
+ const struct iommu_ops *owner; /* Whose domain_alloc we came from */
unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */
struct iommu_domain_geometry geometry;
struct iommu_dma_cookie *iova_cookie;
--
2.39.2.101.g768bb238c484.dirty
\
 
 \ /
  Last update: 2023-09-15 19:00    [W:0.124 / U:2.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site