Re: [PATCH RFC 10/17] acpi: Do not use dev->iommu within acpi_iommu_configure()

[Jason Gunthorpe]

On Sun, Nov 12, 2023 at 09:44:18AM -0800, Moritz Fischer wrote:
> On Fri, Nov 03, 2023 at 01:44:55PM -0300, Jason Gunthorpe 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(),
> Nit: s/acpu_iommu_configure/acpi_iommu_configure_id() ?

Yep

Thanks
Jason

> > 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 
> 
> Reviewed-by: Moritz Fischer 
> > ---
> >  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, ,
> >   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, , 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
> >   

Re: [PATCH RFC 10/17] acpi: Do not use dev->iommu within acpi_iommu_configure()

[Jerry Snitselaar]

Reviewed-by: Jerry Snitselaar 

Re: [PATCH RFC 10/17] acpi: Do not use dev->iommu within acpi_iommu_configure()

[Moritz Fischer]

On Fri, Nov 03, 2023 at 01:44:55PM -0300, Jason Gunthorpe 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(),
Nit: s/acpu_iommu_configure/acpi_iommu_configure_id() ?
> 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 

Reviewed-by: Moritz Fischer 
> ---
>  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, ,
> 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, , 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 = 

Re: [PATCH RFC 10/17] acpi: Do not use dev->iommu within acpi_iommu_configure()

[Rafael J. Wysocki]

On Fri, Nov 3, 2023 at 5:45 PM Jason Gunthorpe  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 

Acked-by: Rafael J. Wysocki 

> ---
>  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, ,
>   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, , 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;
>