Mike Marciniszyn 1bc0299d97 IB/hfi1: Fix user context tail allocation for DMA_RTAIL
The following code fails to allocate a buffer for the
tail address that the hardware DMAs into when the user
context DMA_RTAIL is set.

if (HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL)) {
	rcd->rcvhdrtail_kvaddr = dma_zalloc_coherent(
		&dd->pcidev->dev, PAGE_SIZE, &dma_hdrqtail,
                gfp_flags);
	if (!rcd->rcvhdrtail_kvaddr)
		goto bail_free;
	rcd->rcvhdrqtailaddr_dma = dma_hdrqtail;
}

So the rcvhdrtail_kvaddr would then be NULL.

The mmap logic fails to check for a NULL rcvhdrtail_kvaddr.

The fix is to test for both user and kernel DMA_TAIL options
during the allocation as well as testing for a NULL
rcvhdrtail_kvaddr during the mmap processing.

Additionally, all downstream testing of the capmask for DMA_RTAIL
have been eliminated in favor of testing rcvhdrtail_kvaddr.

Cc: <stable@vger.kernel.org> # 4.9.x
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-06-04 13:33:15 -06:00

Linux kernel
============

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In order to build the documentation, use ``make htmldocs`` or
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See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
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