On Fri, Nov 3, 2023 at 5:45 PM Jason Gunthorpe <jgg@xxxxxxxxxx> wrote:
>
> This call chain is using dev->iommu->fwspec to pass around the fwspec
> between the three parts (acpi_iommu_configure(), acpi_iommu_fwspec_init(),
> iommu_probe_device()).
>
> However there is no locking around the accesses to dev->iommu, so this is
> all racy.
>
> Allocate a clean, local, fwspec at the start of acpu_iommu_configure(),
> pass it through all functions on the stack to fill it with data, and
> finally pass it into iommu_probe_device_fwspec() which will load it into
> dev->iommu under a lock.
>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
> drivers/acpi/arm64/iort.c | 39 ++++++++---------
> drivers/acpi/scan.c | 89 ++++++++++++++++++---------------------
> drivers/acpi/viot.c | 44 ++++++++++---------
> drivers/iommu/iommu.c | 5 +--
> include/acpi/acpi_bus.h | 8 ++--
> include/linux/acpi_iort.h | 3 +-
> include/linux/acpi_viot.h | 5 ++-
> include/linux/iommu.h | 2 +
> 8 files changed, 97 insertions(+), 98 deletions(-)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 6496ff5a6ba20d..accd01dcfe93f5 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1218,10 +1218,9 @@ static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
> return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
> }
>
> -static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
> - u32 streamid)
> +static int iort_iommu_xlate(struct iommu_fwspec *fwspec, struct device *dev,
> + struct acpi_iort_node *node, u32 streamid)
> {
> - const struct iommu_ops *ops;
> struct fwnode_handle *iort_fwnode;
>
> if (!node)
> @@ -1239,17 +1238,14 @@ static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
> * in the kernel or not, defer the IOMMU configuration
> * or just abort it.
> */
> - ops = iommu_ops_from_fwnode(iort_fwnode);
> - if (!ops)
> - return iort_iommu_driver_enabled(node->type) ?
> - -EPROBE_DEFER : -ENODEV;
> -
> - return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
> + return acpi_iommu_fwspec_init(fwspec, dev, streamid, iort_fwnode,
> + iort_iommu_driver_enabled(node->type));
> }
>
> struct iort_pci_alias_info {
> struct device *dev;
> struct acpi_iort_node *node;
> + struct iommu_fwspec *fwspec;
> };
>
> static int iort_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
> @@ -1260,7 +1256,7 @@ static int iort_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
>
> parent = iort_node_map_id(info->node, alias, &streamid,
> IORT_IOMMU_TYPE);
> - return iort_iommu_xlate(info->dev, parent, streamid);
> + return iort_iommu_xlate(info->fwspec, info->dev, parent, streamid);
> }
>
> static void iort_named_component_init(struct device *dev,
> @@ -1280,7 +1276,8 @@ static void iort_named_component_init(struct device *dev,
> dev_warn(dev, "Could not add device properties\n");
> }
>
> -static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node *node)
> +static int iort_nc_iommu_map(struct iommu_fwspec *fwspec, struct device *dev,
> + struct acpi_iort_node *node)
> {
> struct acpi_iort_node *parent;
> int err = -ENODEV, i = 0;
> @@ -1293,13 +1290,13 @@ static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node *node)
> i++);
>
> if (parent)
> - err = iort_iommu_xlate(dev, parent, streamid);
> + err = iort_iommu_xlate(fwspec, dev, parent, streamid);
> } while (parent && !err);
>
> return err;
> }
>
> -static int iort_nc_iommu_map_id(struct device *dev,
> +static int iort_nc_iommu_map_id(struct iommu_fwspec *fwspec, struct device *dev,
> struct acpi_iort_node *node,
> const u32 *in_id)
> {
> @@ -1308,7 +1305,7 @@ static int iort_nc_iommu_map_id(struct device *dev,
>
> parent = iort_node_map_id(node, *in_id, &streamid, IORT_IOMMU_TYPE);
> if (parent)
> - return iort_iommu_xlate(dev, parent, streamid);
> + return iort_iommu_xlate(fwspec, dev, parent, streamid);
>
> return -ENODEV;
> }
> @@ -1322,15 +1319,16 @@ static int iort_nc_iommu_map_id(struct device *dev,
> *
> * Returns: 0 on success, <0 on failure
> */
> -int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
> +int iort_iommu_configure_id(struct iommu_fwspec *fwspec, struct device *dev,
> + const u32 *id_in)
> {
> struct acpi_iort_node *node;
> int err = -ENODEV;
>
> if (dev_is_pci(dev)) {
> - struct iommu_fwspec *fwspec;
> struct pci_bus *bus = to_pci_dev(dev)->bus;
> - struct iort_pci_alias_info info = { .dev = dev };
> + struct iort_pci_alias_info info = { .dev = dev,
> + .fwspec = fwspec };
>
> node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
> iort_match_node_callback, &bus->dev);
> @@ -1341,8 +1339,7 @@ int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
> err = pci_for_each_dma_alias(to_pci_dev(dev),
> iort_pci_iommu_init, &info);
>
> - fwspec = dev_iommu_fwspec_get(dev);
> - if (fwspec && iort_pci_rc_supports_ats(node))
> + if (iort_pci_rc_supports_ats(node))
> fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
> } else {
> node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> @@ -1350,8 +1347,8 @@ int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
> if (!node)
> return -ENODEV;
>
> - err = id_in ? iort_nc_iommu_map_id(dev, node, id_in) :
> - iort_nc_iommu_map(dev, node);
> + err = id_in ? iort_nc_iommu_map_id(fwspec, dev, node, id_in) :
> + iort_nc_iommu_map(fwspec, dev, node);
>
> if (!err)
> iort_named_component_init(dev, node);
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index fbabde001a23a2..1e01a8e0316867 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1543,74 +1543,67 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
> }
>
> #ifdef CONFIG_IOMMU_API
> -int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> - struct fwnode_handle *fwnode,
> - const struct iommu_ops *ops)
> +int acpi_iommu_fwspec_init(struct iommu_fwspec *fwspec, struct device *dev,
> + u32 id, struct fwnode_handle *fwnode,
> + bool iommu_driver_available)
> {
> - int ret = iommu_fwspec_init(dev, fwnode, ops);
> + int ret;
>
> - if (!ret)
> - ret = iommu_fwspec_add_ids(dev, &id, 1);
> -
> - return ret;
> -}
> -
> -static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
> -{
> - struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> -
> - return fwspec ? fwspec->ops : NULL;
> + ret = iommu_fwspec_assign_iommu(fwspec, dev, fwnode);
> + if (ret) {
> + if (ret == -EPROBE_DEFER && !iommu_driver_available)
> + return -ENODEV;
> + return ret;
> + }
> + return iommu_fwspec_append_ids(fwspec, &id, 1);
> }
>
> static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
> {
> int err;
> - const struct iommu_ops *ops;
> + struct iommu_fwspec *fwspec;
>
> - /*
> - * If we already translated the fwspec there is nothing left to do,
> - * return the iommu_ops.
> - */
> - ops = acpi_iommu_fwspec_ops(dev);
> - if (ops)
> - return 0;
> + fwspec = iommu_fwspec_alloc();
> + if (IS_ERR(fwspec))
> + return PTR_ERR(fwspec);
>
> - err = iort_iommu_configure_id(dev, id_in);
> - if (err && err != -EPROBE_DEFER)
> - err = viot_iommu_configure(dev);
> + err = iort_iommu_configure_id(fwspec, dev, id_in);
> + if (err == -ENODEV)
> + err = viot_iommu_configure(fwspec, dev);
> + if (err == -ENODEV || err == -EPROBE_DEFER)
> + goto err_free;
> + if (err)
> + goto err_log;
>
> - /*
> - * If we have reason to believe the IOMMU driver missed the initial
> - * iommu_probe_device() call for dev, replay it to get things in order.
> - */
> - if (!err && dev->bus)
> - err = iommu_probe_device(dev);
> -
> - /* Ignore all other errors apart from EPROBE_DEFER */
> - if (err == -EPROBE_DEFER) {
> - return err;
> - } else if (err) {
> - dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
> - return -ENODEV;
> + err = iommu_probe_device_fwspec(dev, fwspec);
> + if (err) {
> + /*
> + * Ownership for fwspec always passes into
> + * iommu_probe_device_fwspec()
> + */
> + fwspec = NULL;
> + goto err_log;
> }
> - if (!acpi_iommu_fwspec_ops(dev))
> - return -ENODEV;
> - return 0;
> +
> +err_log:
> + dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
> +err_free:
> + iommu_fwspec_dealloc(fwspec);
> + return err;
> }
>
> #else /* !CONFIG_IOMMU_API */
>
> -int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> - struct fwnode_handle *fwnode,
> - const struct iommu_ops *ops)
> +int acpi_iommu_fwspec_init(struct iommu_fwspec *fwspec, struct device *dev,
> + u32 id, struct fwnode_handle *fwnode,
> + bool iommu_driver_available)
> {
> return -ENODEV;
> }
>
> -static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
> - const u32 *id_in)
> +static const int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
> {
> - return NULL;
> + return -ENODEV;
> }
>
> #endif /* !CONFIG_IOMMU_API */
> diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
> index c8025921c129b2..33b511dd202d15 100644
> --- a/drivers/acpi/viot.c
> +++ b/drivers/acpi/viot.c
> @@ -304,11 +304,9 @@ void __init acpi_viot_init(void)
> acpi_put_table(hdr);
> }
>
> -static int viot_dev_iommu_init(struct device *dev, struct viot_iommu *viommu,
> - u32 epid)
> +static int viot_dev_iommu_init(struct iommu_fwspec *fwspec, struct device *dev,
> + struct viot_iommu *viommu, u32 epid)
> {
> - const struct iommu_ops *ops;
> -
> if (!viommu)
> return -ENODEV;
>
> @@ -316,19 +314,20 @@ static int viot_dev_iommu_init(struct device *dev, struct viot_iommu *viommu,
> if (device_match_fwnode(dev, viommu->fwnode))
> return -EINVAL;
>
> - ops = iommu_ops_from_fwnode(viommu->fwnode);
> - if (!ops)
> - return IS_ENABLED(CONFIG_VIRTIO_IOMMU) ?
> - -EPROBE_DEFER : -ENODEV;
> -
> - return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode, ops);
> + return acpi_iommu_fwspec_init(fwspec, dev, epid, viommu->fwnode,
> + IS_ENABLED(CONFIG_VIRTIO_IOMMU));
> }
>
> +struct viot_pci_alias_info {
> + struct device *dev;
> + struct iommu_fwspec *fwspec;
> +};
> +
> static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
> {
> u32 epid;
> struct viot_endpoint *ep;
> - struct device *aliased_dev = data;
> + struct viot_pci_alias_info *info = data;
> u32 domain_nr = pci_domain_nr(pdev->bus);
>
> list_for_each_entry(ep, &viot_pci_ranges, list) {
> @@ -339,14 +338,15 @@ static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
> epid = ((domain_nr - ep->segment_start) << 16) +
> dev_id - ep->bdf_start + ep->endpoint_id;
>
> - return viot_dev_iommu_init(aliased_dev, ep->viommu,
> - epid);
> + return viot_dev_iommu_init(info->fwspec, info->dev,
> + ep->viommu, epid);
> }
> }
> return -ENODEV;
> }
>
> -static int viot_mmio_dev_iommu_init(struct platform_device *pdev)
> +static int viot_mmio_dev_iommu_init(struct iommu_fwspec *fwspec,
> + struct platform_device *pdev)
> {
> struct resource *mem;
> struct viot_endpoint *ep;
> @@ -357,8 +357,8 @@ static int viot_mmio_dev_iommu_init(struct platform_device *pdev)
>
> list_for_each_entry(ep, &viot_mmio_endpoints, list) {
> if (ep->address == mem->start)
> - return viot_dev_iommu_init(&pdev->dev, ep->viommu,
> - ep->endpoint_id);
> + return viot_dev_iommu_init(fwspec, &pdev->dev,
> + ep->viommu, ep->endpoint_id);
> }
> return -ENODEV;
> }
> @@ -369,12 +369,16 @@ static int viot_mmio_dev_iommu_init(struct platform_device *pdev)
> *
> * Return: 0 on success, <0 on failure
> */
> -int viot_iommu_configure(struct device *dev)
> +int viot_iommu_configure(struct iommu_fwspec *fwspec, struct device *dev)
> {
> - if (dev_is_pci(dev))
> + if (dev_is_pci(dev)) {
> + struct viot_pci_alias_info info = { .dev = dev,
> + .fwspec = fwspec };
> return pci_for_each_dma_alias(to_pci_dev(dev),
> - viot_pci_dev_iommu_init, dev);
> + viot_pci_dev_iommu_init, &info);
> + }
> else if (dev_is_platform(dev))
> - return viot_mmio_dev_iommu_init(to_platform_device(dev));
> + return viot_mmio_dev_iommu_init(fwspec,
> + to_platform_device(dev));
> return -ENODEV;
> }
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 15dbe2d9eb24c2..9cfba9d12d1400 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -2960,9 +2960,8 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode)
> return ops;
> }
>
> -static int iommu_fwspec_assign_iommu(struct iommu_fwspec *fwspec,
> - struct device *dev,
> - struct fwnode_handle *iommu_fwnode)
> +int iommu_fwspec_assign_iommu(struct iommu_fwspec *fwspec, struct device *dev,
> + struct fwnode_handle *iommu_fwnode)
> {
> const struct iommu_ops *ops;
>
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 254685085c825c..70f97096c776e4 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -12,6 +12,8 @@
> #include <linux/device.h>
> #include <linux/property.h>
>
> +struct iommu_fwspec;
> +
> /* TBD: Make dynamic */
> #define ACPI_MAX_HANDLES 10
> struct acpi_handle_list {
> @@ -625,9 +627,9 @@ struct acpi_pci_root {
>
> bool acpi_dma_supported(const struct acpi_device *adev);
> enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
> -int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> - struct fwnode_handle *fwnode,
> - const struct iommu_ops *ops);
> +int acpi_iommu_fwspec_init(struct iommu_fwspec *fwspec, struct device *dev,
> + u32 id, struct fwnode_handle *fwnode,
> + bool iommu_driver_available);
> int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map);
> int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
> const u32 *input_id);
> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> index 1cb65592c95dd3..80794ec45d1693 100644
> --- a/include/linux/acpi_iort.h
> +++ b/include/linux/acpi_iort.h
> @@ -40,7 +40,8 @@ void iort_put_rmr_sids(struct fwnode_handle *iommu_fwnode,
> struct list_head *head);
> /* IOMMU interface */
> int iort_dma_get_ranges(struct device *dev, u64 *size);
> -int iort_iommu_configure_id(struct device *dev, const u32 *id_in);
> +int iort_iommu_configure_id(struct iommu_fwspec *fwspec, struct device *dev,
> + const u32 *id_in);
> void iort_iommu_get_resv_regions(struct device *dev, struct list_head *head);
> phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
> #else
> diff --git a/include/linux/acpi_viot.h b/include/linux/acpi_viot.h
> index a5a12243156377..f1874cb6d43c09 100644
> --- a/include/linux/acpi_viot.h
> +++ b/include/linux/acpi_viot.h
> @@ -8,11 +8,12 @@
> #ifdef CONFIG_ACPI_VIOT
> void __init acpi_viot_early_init(void);
> void __init acpi_viot_init(void);
> -int viot_iommu_configure(struct device *dev);
> +int viot_iommu_configure(struct iommu_fwspec *fwspec, struct device *dev);
> #else
> static inline void acpi_viot_early_init(void) {}
> static inline void acpi_viot_init(void) {}
> -static inline int viot_iommu_configure(struct device *dev)
> +static inline int viot_iommu_configure(struct iommu_fwspec *fwspec,
> + struct device *dev)
> {
> return -ENODEV;
> }
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index c5a5e2b5e2cc2a..27e4605d498850 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -688,6 +688,8 @@ void iommu_fwspec_dealloc(struct iommu_fwspec *fwspec);
> int iommu_fwspec_of_xlate(struct iommu_fwspec *fwspec, struct device *dev,
> struct fwnode_handle *iommu_fwnode,
> struct of_phandle_args *iommu_spec);
> +int iommu_fwspec_assign_iommu(struct iommu_fwspec *fwspec, struct device *dev,
> + struct fwnode_handle *iommu_fwnode);
>
> int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
> const struct iommu_ops *ops);
> --
> 2.42.0
>
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