From: Will Deacon <will@kernel.org>
To: linux-kernel@vger.kernel.org, iommu@lists.linuxfoundation.org
Cc: "Isaac J. Manjarres" <isaacm@codeaurora.org>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Saravana Kannan <saravanak@google.com>,
kernel-team@android.com, Robin Murphy <robin.murphy@arm.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH v4 05/16] drivers/iommu: Take a ref to the IOMMU driver prior to ->add_device()
Date: Thu, 19 Dec 2019 12:03:41 +0000 [thread overview]
Message-ID: <20191219120352.382-6-will@kernel.org> (raw)
In-Reply-To: <20191219120352.382-1-will@kernel.org>
To avoid accidental removal of an active IOMMU driver module, take a
reference to the driver module in 'iommu_probe_device()' immediately
prior to invoking the '->add_device()' callback and hold it until the
after the device has been removed by '->remove_device()'.
Suggested-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
drivers/iommu/iommu.c | 19 +++++++++++++++++--
include/linux/iommu.h | 4 +++-
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7c92197d53f3..bc8edf90e729 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -22,6 +22,7 @@
#include <linux/bitops.h>
#include <linux/property.h>
#include <linux/fsl/mc.h>
+#include <linux/module.h>
#include <trace/events/iommu.h>
static struct kset *iommu_group_kset;
@@ -185,10 +186,21 @@ int iommu_probe_device(struct device *dev)
if (!iommu_get_dev_param(dev))
return -ENOMEM;
+ if (!try_module_get(ops->owner)) {
+ ret = -EINVAL;
+ goto err_free_dev_param;
+ }
+
ret = ops->add_device(dev);
if (ret)
- iommu_free_dev_param(dev);
+ goto err_module_put;
+
+ return 0;
+err_module_put:
+ module_put(ops->owner);
+err_free_dev_param:
+ iommu_free_dev_param(dev);
return ret;
}
@@ -199,7 +211,10 @@ void iommu_release_device(struct device *dev)
if (dev->iommu_group)
ops->remove_device(dev);
- iommu_free_dev_param(dev);
+ if (dev->iommu_param) {
+ module_put(ops->owner);
+ iommu_free_dev_param(dev);
+ }
}
static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f2223cbb5fd5..e9f94d3f7a04 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -246,9 +246,10 @@ struct iommu_iotlb_gather {
* @sva_get_pasid: Get PASID associated to a SVA handle
* @page_response: handle page request response
* @cache_invalidate: invalidate translation caches
- * @pgsize_bitmap: bitmap of all possible supported page sizes
* @sva_bind_gpasid: bind guest pasid and mm
* @sva_unbind_gpasid: unbind guest pasid and mm
+ * @pgsize_bitmap: bitmap of all possible supported page sizes
+ * @owner: Driver module providing these ops
*/
struct iommu_ops {
bool (*capable)(enum iommu_cap);
@@ -318,6 +319,7 @@ struct iommu_ops {
int (*sva_unbind_gpasid)(struct device *dev, int pasid);
unsigned long pgsize_bitmap;
+ struct module *owner;
};
/**
--
2.24.1.735.g03f4e72817-goog
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iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2019-12-19 12:04 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 12:03 [PATCH v4 00/16] iommu: Permit modular builds of ARM SMMU[v3] drivers Will Deacon
2019-12-19 12:03 ` [PATCH v4 01/16] drivers/iommu: Export core IOMMU API symbols to permit modular drivers Will Deacon
2019-12-19 12:03 ` [PATCH v4 02/16] iommu/of: Request ACS from the PCI core when configuring IOMMU linkage Will Deacon
2019-12-19 12:03 ` [PATCH v4 03/16] PCI/ATS: Restore EXPORT_SYMBOL_GPL() for pci_{enable, disable}_ats() Will Deacon
2019-12-20 8:43 ` [PATCH v4 03/16] PCI/ATS: Restore EXPORT_SYMBOL_GPL() for pci_{enable,disable}_ats() Joerg Roedel
2019-12-20 15:03 ` Bjorn Helgaas
2019-12-19 12:03 ` [PATCH v4 04/16] PCI: Export pci_ats_disabled() as a GPL symbol to modules Will Deacon
2019-12-19 12:03 ` Will Deacon [this message]
2019-12-19 14:44 ` [PATCH v4 05/16] drivers/iommu: Take a ref to the IOMMU driver prior to ->add_device() Greg Kroah-Hartman
2020-01-09 14:16 ` Will Deacon
2020-01-09 18:17 ` Greg Kroah-Hartman
2019-12-19 12:03 ` [PATCH v4 06/16] iommu/of: Take a ref to the IOMMU driver during ->of_xlate() Will Deacon
2019-12-19 12:03 ` [PATCH v4 07/16] drivers/iommu: Allow IOMMU bus ops to be unregistered Will Deacon
2019-12-19 12:03 ` [PATCH v4 08/16] Revert "iommu/arm-smmu: Make arm-smmu-v3 explicitly non-modular" Will Deacon
2019-12-19 12:03 ` [PATCH v4 09/16] Revert "iommu/arm-smmu: Make arm-smmu " Will Deacon
2019-12-19 12:03 ` [PATCH v4 10/16] iommu/arm-smmu: Prevent forced unbinding of Arm SMMU drivers Will Deacon
2019-12-19 12:03 ` [PATCH v4 11/16] iommu/arm-smmu-v3: Unregister IOMMU and bus ops on device removal Will Deacon
2019-12-19 12:03 ` [PATCH v4 12/16] iommu/arm-smmu: Support SMMU module probing from the IORT Will Deacon
2019-12-19 12:03 ` [PATCH v4 13/16] iommu/arm-smmu-v3: Allow building as a module Will Deacon
2019-12-19 12:03 ` [PATCH v4 14/16] iommu/arm-smmu: Unregister IOMMU and bus ops on device removal Will Deacon
2019-12-19 12:03 ` [PATCH v4 15/16] iommu/arm-smmu: Allow building as a module Will Deacon
2019-12-19 12:03 ` [PATCH v4 16/16] iommu/arm-smmu: Update my email address in MODULE_AUTHOR() Will Deacon
2019-12-19 12:12 ` [PATCH v4 00/16] iommu: Permit modular builds of ARM SMMU[v3] drivers John Garry
2019-12-19 14:44 ` Greg Kroah-Hartman
2019-12-20 16:13 ` Joerg Roedel
2020-01-06 10:48 ` Will Deacon
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