search for: dma_addressing_limit

We currently have cases where the dma_addressing_limited() gets called with dma_mask unset. This causes a NULL pointer dereference. Use dma_get_mask() accessor to prevent the crash. Fixes: b866455423e0 ("dma-mapping: add a dma_addressing_limited helper") Signed-off-by: Eric Auger <eric.auger at redhat.com> --- v1 -> v2: - was [PA...

We currently have cases where the dma_addressing_limited() gets called with dma_mask unset. This causes a NULL pointer dereference. Use dma_get_mask() accessor to prevent the crash. Fixes: b866455423e0 ("dma-mapping: add a dma_addressing_limited helper") Signed-off-by: Eric Auger <eric.auger at redhat.com> --- v1 -> v2: - was [PA...

Hi Christoph, On 7/22/19 6:51 PM, Eric Auger wrote: > We currently have cases where the dma_addressing_limited() gets > called with dma_mask unset. This causes a NULL pointer dereference. > > Use dma_get_mask() accessor to prevent the crash. > > Fixes: b866455423e0 ("dma-mapping: add a dma_addressing_limited helper") > Signed-off-by: Eric Auger <eric.auger at redhat.com&gt...

dma_addressing_limited() should not be called on a device with a NULL dma_mask. If this occurs let's WARN_ON_ONCE and immediately return. Existing call sites are updated separately. Fixes: b866455423e0 ("dma-mapping: add a dma_addressing_limited helper") Signed-off-by: Eric Auger <eric.auger at redhat...

> static inline bool dma_addressing_limited(struct device *dev) > { > - return min_not_zero(*dev->dma_mask, dev->bus_dma_mask) < > - dma_get_required_mask(dev); > + return WARN_ON_ONCE(!dev->dma_mask) ? false : > + min_not_zero(*dev->dma_mask, dev->bus_dma_mask) < > + dma_get_required_mask(dev);...

When running a guest featuring a virtio-blk-pci protected with a virtual IOMMU we hit a NULL pointer dereference. This series removes the dma_max_mapping_size() call in virtio_max_dma_size when the device does not have any dma_mask set. A check is also added to early return in dma_addressing_limited() if the dma_mask is NULL. Eric Auger (2): dma-mapping: Protect dma_addressing_limited against NULL dma_mask virtio/virtio_ring: Fix the dma_max_mapping_size call drivers/virtio/virtio_ring.c | 2 +- include/linux/dma-mapping.h | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-)...

...the Protected Execution Facility, with the help of an Ultravisor > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index f7d1eea..6df5664 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -693,6 +693,26 @@ static inline bool dma_addressing_limited(struct device *dev) > dma_get_required_mask(dev); > } > > +#ifndef CONFIG_ARCH_HAS_DMA_ADDR_IS_PHYS_ADDR > +/** > + * dma_addr_is_phys_addr - check whether a device DMA address is a physical > + * address > + * @dev: device to check > + * > + * Returns %t...

...the Protected Execution Facility, with the help of an Ultravisor > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index f7d1eea..6df5664 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -693,6 +693,26 @@ static inline bool dma_addressing_limited(struct device *dev) > dma_get_required_mask(dev); > } > > +#ifndef CONFIG_ARCH_HAS_DMA_ADDR_IS_PHYS_ADDR > +/** > + * dma_addr_is_phys_addr - check whether a device DMA address is a physical > + * address > + * @dev: device to check > + * > + * Returns %t...

...rt secure guests using the Protected Execution Facility, with the help of an Ultravisor diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index f7d1eea..6df5664 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -693,6 +693,26 @@ static inline bool dma_addressing_limited(struct device *dev) dma_get_required_mask(dev); } +#ifndef CONFIG_ARCH_HAS_DMA_ADDR_IS_PHYS_ADDR +/** + * dma_addr_is_phys_addr - check whether a device DMA address is a physical + * address + * @dev: device to check + * + * Returns %true if any DMA address for this device happens to...

...tion Facility, with the help of an Ultravisor >> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h >> index f7d1eea..6df5664 100644 >> --- a/include/linux/dma-mapping.h >> +++ b/include/linux/dma-mapping.h >> @@ -693,6 +693,26 @@ static inline bool dma_addressing_limited(struct device *dev) >> dma_get_required_mask(dev); >> } >> >> +#ifndef CONFIG_ARCH_HAS_DMA_ADDR_IS_PHYS_ADDR >> +/** >> + * dma_addr_is_phys_addr - check whether a device DMA address is a physical >> + * address >> + * @dev: device to...

On 22/07/2019 15:55, Eric Auger wrote: > Do not call dma_max_mapping_size for devices that have no DMA > mask set, otherwise we can hit a NULL pointer dereference. > > This occurs when a virtio-blk-pci device is protected with > a virtual IOMMU. > > Fixes: e6d6dd6c875e ("virtio: Introduce virtio_max_dma_size()") > Signed-off-by: Eric Auger <eric.auger at

On 22/07/2019 15:55, Eric Auger wrote: > Do not call dma_max_mapping_size for devices that have no DMA > mask set, otherwise we can hit a NULL pointer dereference. > > This occurs when a virtio-blk-pci device is protected with > a virtual IOMMU. > > Fixes: e6d6dd6c875e ("virtio: Introduce virtio_max_dma_size()") > Signed-off-by: Eric Auger <eric.auger at

**We would like the patches to be merged through the virtio tree. Please review, and ack merging the DMA mapping change through that tree. Thanks!** The memory of powerpc secure guests can't be accessed by the hypervisor / virtio device except for a few memory regions designated as 'shared'. At the moment, Linux uses bounce-buffering to communicate with the hypervisor, with a