From: Will Deacon <will@kernel.org>
To: iommu@lists.linuxfoundation.org, linux-kernel@vger.kernel.org
Cc: Will Deacon <will@kernel.org>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Jordan Crouse <jcrouse@codeaurora.org>,
John Garry <john.garry@huawei.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Saravana Kannan <saravanak@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Isaac J. Manjarres" <isaacm@codeaurora.org>,
Robin Murphy <robin.murphy@arm.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Joerg Roedel <joro@8bytes.org>
Subject: [PATCH v3 04/14] drivers/iommu: Take a ref to the IOMMU driver prior to ->add_device()
Date: Thu, 21 Nov 2019 11:49:08 +0000 [thread overview]
Message-ID: <20191121114918.2293-5-will@kernel.org> (raw)
In-Reply-To: <20191121114918.2293-1-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 | 2 ++
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c1aadb570145..4bfecfbbe2cf 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 29bac5345563..d9dab5a3e912 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -245,6 +245,7 @@ struct iommu_iotlb_gather {
* @sva_get_pasid: Get PASID associated to a SVA handle
* @page_response: handle page request response
* @pgsize_bitmap: bitmap of all possible supported page sizes
+ * @owner: Driver module providing these ops
*/
struct iommu_ops {
bool (*capable)(enum iommu_cap);
@@ -308,6 +309,7 @@ struct iommu_ops {
struct iommu_page_response *msg);
unsigned long pgsize_bitmap;
+ struct module *owner;
};
/**
--
2.24.0.432.g9d3f5f5b63-goog
next prev parent reply other threads:[~2019-11-21 11:49 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-21 11:49 [PATCH v3 00/14] iommu: Permit modular builds of ARM SMMU[v3] drivers Will Deacon
2019-11-21 11:49 ` [PATCH v3 01/14] drivers/iommu: Export core IOMMU API symbols to permit modular drivers Will Deacon
2019-11-21 11:49 ` [PATCH v3 02/14] iommu/of: Request ACS from the PCI core when configuring IOMMU linkage Will Deacon
2019-11-21 11:49 ` [PATCH v3 03/14] PCI: Export pci_ats_disabled() as a GPL symbol to modules Will Deacon
2019-11-21 11:49 ` Will Deacon [this message]
2019-11-21 11:49 ` [PATCH v3 05/14] iommu/of: Take a ref to the IOMMU driver during ->of_xlate() Will Deacon
2019-11-21 11:49 ` [PATCH v3 06/14] drivers/iommu: Allow IOMMU bus ops to be unregistered Will Deacon
2019-11-21 11:49 ` [PATCH v3 07/14] Revert "iommu/arm-smmu: Make arm-smmu-v3 explicitly non-modular" Will Deacon
2019-11-21 11:49 ` [PATCH v3 08/14] Revert "iommu/arm-smmu: Make arm-smmu " Will Deacon
2019-11-21 11:49 ` [PATCH v3 09/14] iommu/arm-smmu: Prevent forced unbinding of Arm SMMU drivers Will Deacon
2019-11-26 9:13 ` John Garry
2019-11-26 20:27 ` Saravana Kannan
2019-11-27 11:04 ` John Garry
2019-11-27 11:41 ` John Garry
2019-11-21 11:49 ` [PATCH v3 10/14] iommu/arm-smmu-v3: Unregister IOMMU and bus ops on device removal Will Deacon
2019-11-21 11:49 ` [PATCH v3 11/14] iommu/arm-smmu-v3: Allow building as a module Will Deacon
2019-11-21 11:49 ` [PATCH v3 12/14] iommu/arm-smmu: Unregister IOMMU and bus ops on device removal Will Deacon
2019-11-21 11:49 ` [PATCH v3 13/14] iommu/arm-smmu: Allow building as a module Will Deacon
2019-11-21 11:49 ` [PATCH v3 14/14] iommu/arm-smmu: Update my email address in MODULE_AUTHOR() Will Deacon
2019-11-22 17:41 ` [PATCH] iommu/arm-smmu: support SMMU module probing from the IORT Ard Biesheuvel
2019-11-25 12:16 ` Robin Murphy
2019-11-25 16:04 ` Lorenzo Pieralisi
2019-11-27 16:20 ` John Garry
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