<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/dma-mapping.h, branch v4.9.333</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2022-06-25T09:45:19Z</updated>
<entry>
<title>Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""</title>
<updated>2022-06-25T09:45:19Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-28T18:37:05Z</published>
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<id>urn:sha1:fd97de9c7b973f46a6103f4170c5efc7b8ef8797</id>
<content type='text'>
commit 901c7280ca0d5e2b4a8929fbe0bfb007ac2a6544 upstream.

Halil Pasic points out [1] that the full revert of that commit (revert
in bddac7c1e02b), and that a partial revert that only reverts the
problematic case, but still keeps some of the cleanups is probably
better.  ￼

And that partial revert [2] had already been verified by Oleksandr
Natalenko to also fix the issue, I had just missed that in the long
discussion.

So let's reinstate the cleanups from commit aa6f8dcbab47 ("swiotlb:
rework "fix info leak with DMA_FROM_DEVICE""), and effectively only
revert the part that caused problems.

Link: https://lore.kernel.org/all/20220328013731.017ae3e3.pasic@linux.ibm.com/ [1]
Link: https://lore.kernel.org/all/20220324055732.GB12078@lst.de/ [2]
Link: https://lore.kernel.org/all/4386660.LvFx2qVVIh@natalenko.name/ [3]
Suggested-by: Halil Pasic &lt;pasic@linux.ibm.com&gt;
Tested-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
[OP: backport to 4.14: apply swiotlb_tbl_map_single() changes in lib/swiotlb.c]
Signed-off-by: Ovidiu Panait &lt;ovidiu.panait@windriver.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>swiotlb: fix info leak with DMA_FROM_DEVICE</title>
<updated>2022-06-25T09:45:19Z</updated>
<author>
<name>Halil Pasic</name>
<email>pasic@linux.ibm.com</email>
</author>
<published>2022-02-11T01:12:52Z</published>
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<id>urn:sha1:c132f2ba716b5ee6b35f82226a6e5417d013d753</id>
<content type='text'>
commit ddbd89deb7d32b1fbb879f48d68fda1a8ac58e8e upstream.

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 a45b599ad808 ("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 &lt;pasic@linux.ibm.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
[OP: backport to 4.14: apply swiotlb_tbl_map_single() changes in lib/swiotlb.c]
Signed-off-by: Ovidiu Panait &lt;ovidiu.panait@windriver.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>dma-mapping: fix return type of dma_set_max_seg_size()</title>
<updated>2019-12-21T09:41:09Z</updated>
<author>
<name>Niklas Söderlund</name>
<email>niklas.soderlund+renesas@ragnatech.se</email>
</author>
<published>2018-08-29T21:29:21Z</published>
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<id>urn:sha1:dafd9e94580c6fdcc27b5750b6d2c1987ca46f5a</id>
<content type='text'>
[ Upstream commit c9d76d0655c06b8c1f944e46c4fd9e9cf4b331c0 ]

The function dma_set_max_seg_size() can return either 0 on success or
-EIO on error. Change its return type from unsigned int to int to
capture this.

Signed-off-by: Niklas Söderlund &lt;niklas.soderlund+renesas@ragnatech.se&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>scsi: dma-mapping: always provide dma_get_cache_alignment</title>
<updated>2017-12-14T08:28:11Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2017-11-21T13:23:37Z</published>
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<id>urn:sha1:4cb4d78c57f8ba642b5071d439d71217291d9e71</id>
<content type='text'>
commit 860dd4424f344400b491b212ee4acb3a358ba9d9 upstream.

Provide the dummy version of dma_get_cache_alignment that always returns
1 even if CONFIG_HAS_DMA is not set, so that drivers and subsystems can
use it without ifdefs.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dma-mapping: introduce the DMA_ATTR_NO_WARN attribute</title>
<updated>2016-10-11T22:06:32Z</updated>
<author>
<name>Mauricio Faria de Oliveira</name>
<email>mauricfo@linux.vnet.ibm.com</email>
</author>
<published>2016-10-11T20:54:14Z</published>
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<id>urn:sha1:a9a62c9384417545620aee1b5ad1d9357350c17a</id>
<content type='text'>
Introduce the DMA_ATTR_NO_WARN attribute, and document it.

Link: http://lkml.kernel.org/r/1470092390-25451-2-git-send-email-mauricfo@linux.vnet.ibm.com
Signed-off-by: Mauricio Faria de Oliveira &lt;mauricfo@linux.vnet.ibm.com&gt;
Cc: Keith Busch &lt;keith.busch@intel.com&gt;
Cc: Jens Axboe &lt;axboe@fb.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Krzysztof Kozlowski &lt;k.kozlowski@samsung.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'dmaengine-4.9-rc1' of git://git.infradead.org/users/vkoul/slave-dma</title>
<updated>2016-10-07T00:13:54Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-10-07T00:13:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=553911c67eb701d46e2dcd073f603c6f6546c38b'/>
<id>urn:sha1:553911c67eb701d46e2dcd073f603c6f6546c38b</id>
<content type='text'>
Pull dmaengine updates from Vinod Koul:
 "This is bit large pile of code which bring in some nice additions:

   - Error reporting: we have added a new mechanism for users of
     dmaenegine to register a callback_result which tells them the
     result of the dma transaction. Right now only one user (ntb) is
     using it.

   - As we discussed on KS mailing list and pointed out NO_IRQ has no
     place in kernel, this also remove NO_IRQ from dmaengine subsystem
     (both arm and ppc users)

   - Support for IOMMU slave transfers and its implementation for arm.

   - To get better build coverage, enable COMPILE_TEST for bunch of
     driver, and fix the warning and sparse complaints on these.

   - Apart from above, usual updates spread across drivers"

* tag 'dmaengine-4.9-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (169 commits)
  async_pq_val: fix DMA memory leak
  dmaengine: virt-dma: move function declarations
  dmaengine: omap-dma: Enable burst and data pack for SG
  DT: dmaengine: rcar-dmac: document R8A7743/5 support
  dmaengine: fsldma: Unmap region obtained by of_iomap
  dmaengine: jz4780: fix resource leaks on error exit return
  dma-debug: fix ia64 build, use PHYS_PFN
  dmaengine: coh901318: fix integer overflow when shifting more than 32 places
  dmaengine: edma: avoid uninitialized variable use
  dma-mapping: fix m32r build warning
  dma-mapping: fix ia64 build, use PHYS_PFN
  dmaengine: ti-dma-crossbar: enable COMPILE_TEST
  dmaengine: omap-dma: enable COMPILE_TEST
  dmaengine: edma: enable COMPILE_TEST
  dmaengine: ti-dma-crossbar: Fix of_device_id data parameter usage
  dmaengine: ti-dma-crossbar: Correct type for of_find_property() third parameter
  dmaengine/ARM: omap-dma: Fix the DMAengine compile test on non OMAP configs
  dmaengine: edma: Rename set_bits and remove unused clear_bits helper
  dmaengine: edma: Use correct type for of_find_property() third parameter
  dmaengine: edma: Fix of_device_id data parameter usage (legacy vs TPCC)
  ...
</content>
</entry>
<entry>
<title>dma-mapping: fix m32r build warning</title>
<updated>2016-09-29T12:08:02Z</updated>
<author>
<name>Niklas Söderlund</name>
<email>niklas.soderlund+renesas@ragnatech.se</email>
</author>
<published>2016-09-29T10:02:40Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3757dc48a66f829cf6ba82a612ba4587ab4b5f1c'/>
<id>urn:sha1:3757dc48a66f829cf6ba82a612ba4587ab4b5f1c</id>
<content type='text'>
kbuild test robot reports:

   In file included from include/linux/skbuff.h:34:0,
                    from include/linux/icmpv6.h:4,
                    from include/linux/ipv6.h:75,
                    from include/net/ipv6.h:16,
                    from include/linux/sunrpc/clnt.h:27,
                    from include/linux/nfs_fs.h:30,
                    from fs/lockd/clntlock.c:13:
   include/linux/dma-mapping.h: In function 'dma_map_resource':
&gt;&gt; include/linux/dma-mapping.h:274:16: warning: unused variable 'pfn' [-Wunused-variable]
     unsigned long pfn = __phys_to_pfn(phys_addr);
                   ^~~

The pfn value is only used once in the call to pfn_valid(), remove the
variable and calculate the pfn when it's needed. Note that the kbuild
report is old and PHYS_PFN() is now used instead of __phys_to_pfn() to
calculate the pfn.

Signed-off-by: Niklas Söderlund &lt;niklas.soderlund+renesas@ragnatech.se&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</content>
</entry>
<entry>
<title>dma-mapping: fix ia64 build, use PHYS_PFN</title>
<updated>2016-09-29T12:08:02Z</updated>
<author>
<name>Niklas Söderlund</name>
<email>niklas.soderlund+renesas@ragnatech.se</email>
</author>
<published>2016-09-29T10:02:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2895e1f8048d1be7b1b5be6439c740621c0e5361'/>
<id>urn:sha1:2895e1f8048d1be7b1b5be6439c740621c0e5361</id>
<content type='text'>
kbuild test robot reports:

   In file included from include/linux/skbuff.h:34:0,
                    from include/linux/tcp.h:21,
                    from drivers/net/ethernet/amd/xgbe/xgbe-drv.c:119:
   include/linux/dma-mapping.h: In function 'dma_map_resource':
&gt;&gt; include/linux/dma-mapping.h:274:22: error: implicit declaration of function '__phys_to_pfn' [-Werror=implicit-function-declaration]
     unsigned long pfn = __phys_to_pfn(phys_addr);
                         ^~~~~~~~~~~~~

ia64 does not provide __phys_to_pfn(), use the PHYS_PFN() alias.

Signed-off-by: Niklas Söderlund &lt;niklas.soderlund+renesas@ragnatech.se&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</content>
</entry>
<entry>
<title>dma-mapping.h: preserve unmap info for CONFIG_DMA_API_DEBUG</title>
<updated>2016-09-28T23:19:01Z</updated>
<author>
<name>Andrey Smirnov</name>
<email>andrew.smirnov@gmail.com</email>
</author>
<published>2016-09-28T22:22:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2481366afd71a0c0b7cd725e6750c04cf589673b'/>
<id>urn:sha1:2481366afd71a0c0b7cd725e6750c04cf589673b</id>
<content type='text'>
When CONFIG_DMA_API_DEBUG is enabled we need to preserve unmapping address
even if "unmap" is a no-op for our architecutre because we need
debug_dma_unmap_page() to correctly cleanup all of the debug bookkeeping.
Failing to do so results in a false positive warnings about previously
mapped areas never being unmapped.

Link: http://lkml.kernel.org/r/1474387125-3713-1-git-send-email-andrew.smirnov@gmail.com
Signed-off-by: Andrey Smirnov &lt;andrew.smirnov@gmail.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Joerg Roedel &lt;jroedel@suse.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Cc: "Luis R. Rodriguez" &lt;mcgrof@suse.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Geliang Tang &lt;geliangtang@163.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>dma-mapping: add dma_{map,unmap}_resource</title>
<updated>2016-09-26T16:46:41Z</updated>
<author>
<name>Niklas Söderlund</name>
<email>niklas.soderlund+renesas@ragnatech.se</email>
</author>
<published>2016-08-10T11:22:16Z</published>
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<id>urn:sha1:6f3d87968f9c8b529bc81eff5a1f45e92553493d</id>
<content type='text'>
Map/Unmap a device MMIO resource from a physical address. If no dma_map_ops
method is available the operation is a no-op.

Signed-off-by: Niklas Söderlund &lt;niklas.soderlund+renesas@ragnatech.se&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</content>
</entry>
</feed>
