The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO
interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV
and a corresponding dxferp. The peculiar thing about this is that TUR
is not reading from the device.
2) In sg_start_req() the invocation of blk_rq_map_user() effectively
bounces the user-space buffer. As if the device was to transfer into
it. Since commit a45b599ad8 ("scsi: sg: allocate with __GFP_ZERO in
sg_build_indirect()") we make sure this first bounce buffer is
allocated with GFP_ZERO.
3) For the rest of the story we keep ignoring that we have a TUR, so the
device won't touch the buffer we prepare as if the we had a
DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device
and the buffer allocated by SG is mapped by the function
virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here
scatter-gather and not scsi generics). This mapping involves bouncing
via the swiotlb (we need swiotlb to do virtio in protected guest like
s390 Secure Execution, or AMD SEV).
4) When the SCSI TUR is done, we first copy back the content of the second
(that is swiotlb) bounce buffer (which most likely contains some
previous IO data), to the first bounce buffer, which contains all
zeros. Then we copy back the content of the first bounce buffer to
the user-space buffer.
5) The test case detects that the buffer, which it zero-initialized,
ain't all zeros and fails.
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
These can only return 0 for failure or the number of entries, so turn
the return value into an unsigned int.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Allow dma_map_sgtable() to pass errors from the map_sg() ops. This
will be required for returning appropriate error codes when mapping
P2PDMA memory.
Introduce __dma_map_sg_attrs() which will return the raw error code
from the map_sg operation (whether it be negative or zero). Then add a
dma_map_sg_attrs() wrapper to convert any negative errors to zero to
satisfy the existing calling convention.
dma_map_sgtable() defines three error codes that .map_sg implementations
are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which
is a generic return for cases that are passing DMA_MAPPING_ERROR
through.
dma_map_sgtable() will convert a zero error return for old map_sg() ops
into a -EIO return and return any negative errors as reported.
This allows map_sg implementations to start returning multiple
negative error codes. Legacy map_sg implementations can continue
to return zero until they are all converted.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Zillions of drivers use the unlikely() hint when checking the result of
dma_mapping_error(). This is an inline function anyway, so we can move
the hint into the function and remove it from drivers over time.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add a new API that returns a potentiall virtually non-contigous sg_table
and a DMA address. This API is only properly implemented for dma-iommu
and will simply return a contigious chunk as a fallback.
The intent is that drivers can use this API if either:
- no kernel mapping or only temporary kernel mappings are required.
That is as a better replacement for DMA_ATTR_NO_KERNEL_MAPPING
- a kernel mapping is required for cached and DMA mapped pages, but
the driver also needs the pages to e.g. map them to userspace.
In that sense it is a replacement for some aspects of the recently
removed and never fully implemented DMA_ATTR_NON_CONSISTENT
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>
Add a helper to map memory allocated using dma_alloc_pages into
a user address space, similar to the dma_alloc_attrs function for
coherent allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>
Pull swiotlb updates from Konrad Rzeszutek Wilk:
"Two memory encryption related patches (SWIOTLB is enabled by default
for AMD-SEV):
- Add support for alignment so that NVME can properly work
- Keep track of requested DMA buffers length, as underlaying hardware
devices can trip SWIOTLB to bounce too much and crash the kernel
And a tiny fix to use proper APIs in drivers"
* 'stable/for-linus-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: Validate bounce size in the sync/unmap path
nvme-pci: set min_align_mask
swiotlb: respect min_align_mask
swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single
swiotlb: refactor swiotlb_tbl_map_single
swiotlb: clean up swiotlb_tbl_unmap_single
swiotlb: factor out a nr_slots helper
swiotlb: factor out an io_tlb_offset helper
swiotlb: add a IO_TLB_SIZE define
driver core: add a min_align_mask field to struct device_dma_parameters
sdhci: stop poking into swiotlb internals
Some devices rely on the address offset in a page to function
correctly (NVMe driver as an example). These devices may use
a different page size than the Linux kernel. The address offset
has to be preserved upon mapping, and in order to do so, we
need to record the page_offset_mask first.
Signed-off-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
It turns out allowing non-contigous allocations here was a rather bad
idea, as we'll now need to define ways to get the pages for mmaping
or dma_buf sharing. Revert this change and stick to the original
concept. A different API for the use case of non-contigous allocations
will be added back later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>:wq
Pull ARM SoC driver updates from Arnd Bergmann:
"There are a couple of subsystems maintained by other people that merge
their drivers through the SoC tree, those changes include:
- The SCMI firmware framework gains support for sensor notifications
and for controlling voltage domains.
- A large update for the Tegra memory controller driver, integrating
it better with the interconnect framework
- The memory controller subsystem gains support for Mediatek MT8192
- The reset controller framework gains support for sharing pulsed
resets
For Soc specific drivers in drivers/soc, the main changes are
- The Allwinner/sunxi MBUS gets a rework for the way it handles
dma_map_ops and offsets between physical and dma address spaces.
- An errata fix plus some cleanups for Freescale Layerscape SoCs
- A cleanup for renesas drivers regarding MMIO accesses.
- New SoC specific drivers for Mediatek MT8192 and MT8183 power
domains
- New SoC specific drivers for Aspeed AST2600 LPC bus control and SoC
identification.
- Core Power Domain support for Qualcomm MSM8916, MSM8939, SDM660 and
SDX55.
- A rework of the TI AM33xx 'genpd' power domain support to use
information from DT instead of platform data
- Support for TI AM64x SoCs
- Allow building some Amlogic drivers as modules instead of built-in
Finally, there are numerous cleanups and smaller bug fixes for
Mediatek, Tegra, Samsung, Qualcomm, TI OMAP, Amlogic, Rockchips,
Renesas, and Xilinx SoCs"
* tag 'arm-soc-drivers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (222 commits)
soc: mediatek: mmsys: Specify HAS_IOMEM dependency for MTK_MMSYS
firmware: xilinx: Properly align function parameter
firmware: xilinx: Add a blank line after function declaration
firmware: xilinx: Remove additional newline
firmware: xilinx: Fix kernel-doc warnings
firmware: xlnx-zynqmp: fix compilation warning
soc: xilinx: vcu: add missing register NUM_CORE
soc: xilinx: vcu: use vcu-settings syscon registers
dt-bindings: soc: xlnx: extract xlnx, vcu-settings to separate binding
soc: xilinx: vcu: drop useless success message
clk: samsung: mark PM functions as __maybe_unused
soc: samsung: exynos-chipid: initialize later - with arch_initcall
soc: samsung: exynos-chipid: order list of SoCs by name
memory: jz4780_nemc: Fix potential NULL dereference in jz4780_nemc_probe()
memory: ti-emif-sram: only build for ARMv7
memory: tegra30: Support interconnect framework
memory: tegra20: Support hardware versioning and clean up OPP table initialization
dt-bindings: memory: tegra20-emc: Document opp-supported-hw property
soc: rockchip: io-domain: Fix error return code in rockchip_iodomain_probe()
reset-controller: ti: force the write operation when assert or deassert
...
Drop the dma_direct_set_offset export and move the declaration to
dma-map-ops.h now that the Allwinner drivers have stopped calling it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Due to a mismerge a bunch of prototypes that should have moved to
dma-map-ops.h are still in dma-mapping.h, fix that up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Most of dma-debug.h is not required by anything outside of kernel/dma.
Move the four declarations needed by dma-mappin.h or dma-ops providers
into dma-mapping.h and dma-map-ops.h, and move the remainder of the
file to kernel/dma/debug.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Split out all the bits that are purely for dma_map_ops implementations
and related code into a new <linux/dma-map-ops.h> header so that they
don't get pulled into all the drivers. That also means the architecture
specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h>
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
This API is the equivalent of alloc_pages, except that the returned memory
is guaranteed to be DMA addressable by the passed in device. The
implementation will also be used to provide a more sensible replacement
for DMA_ATTR_NON_CONSISTENT flag.
Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages
as its backend.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
All users are gone now, remove the API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
Add a new API to allocate and free memory that is guaranteed to be
addressable by a device, but which potentially is not cache coherent
for DMA.
To transfer ownership to and from the device, the existing streaming
DMA API calls dma_sync_single_for_device and dma_sync_single_for_cpu
must be used.
For now the new calls are implemented on top of dma_alloc_attrs just
like the old-noncoherent API, but once all drivers are switched to
the new API it will be replaced with a better working implementation
that is available on all architectures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Move the comment documenting dma_addr_t away from the dma_map_ops
definition which isn't very related to it, and toward DMA_MAPPING_ERROR,
which is somewhat related. Add a little blurb about DMA_MAPPING_ERROR
as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Move the valid_dma_direction helper to a more suitable header, and
clean it up to use the proper enum as well as removing pointless braces.
Signed-off-by: Christoph Hellwig <hch@lst.de>
This value is only used by a PCMCIA driver and not very useful.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dominik Brodowski <linux@dominikbrodwski.net>
The new field 'dma_range_map' in struct device is used to facilitate the
use of single or multiple offsets between mapping regions of cpu addrs and
dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only
capable of holding a single uniform offset and had no region bounds
checking.
The function of_dma_get_range() has been modified so that it takes a single
argument -- the device node -- and returns a map, NULL, or an error code.
The map is an array that holds the information regarding the DMA regions.
Each range entry contains the address offset, the cpu_start address, the
dma_start address, and the size of the region.
of_dma_configure() is the typical manner to set range offsets but there are
a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel
driver code. These cases now invoke the function
dma_direct_set_offset(dev, cpu_addr, dma_addr, size).
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
[hch: various interface cleanups]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
The default segment_boundary_mask was set to DMA_BIT_MAKS(32)
a decade ago by referencing SCSI/block subsystem, as a 32-bit
mask was good enough for most of the devices.
Now more and more drivers set dma_masks above DMA_BIT_MAKS(32)
while only a handful of them call dma_set_seg_boundary(). This
means that most drivers have a 4GB segmention boundary because
DMA API returns a 32-bit default value, though they might not
really have such a limit.
The default segment_boundary_mask should mean "no limit" since
the device doesn't explicitly set the mask. But a 32-bit mask
certainly limits those devices capable of 32+ bits addressing.
So this patch sets default segment_boundary_mask to ULONG_MAX.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Halil Pasic
Christoph Hellwig
Logan Gunthorpe
Heiner Kallweit
Wang Qing
Linus Torvalds
Jianxiong Gao
Jim Quinlan
Nicolin Chen