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>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index 3feecf926322..4a478ee0a79b 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -1853,7 +1853,6 @@ int hfi1_create_rcvhdrq(struct hfi1_devdata *dd, struct hfi1_ctxtdata *rcd)
 	u64 reg;
 
 	if (!rcd->rcvhdrq) {
-		dma_addr_t dma_hdrqtail;
 		gfp_t gfp_flags;
 
 		/*
@@ -1878,13 +1877,13 @@ int hfi1_create_rcvhdrq(struct hfi1_devdata *dd, struct hfi1_ctxtdata *rcd)
 			goto bail;
 		}
 
-		if (HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL)) {
+		if (HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL) ||
+		    HFI1_CAP_UGET_MASK(rcd->flags, DMA_RTAIL)) {
 			rcd->rcvhdrtail_kvaddr = dma_zalloc_coherent(
-				&dd->pcidev->dev, PAGE_SIZE, &dma_hdrqtail,
-				gfp_flags);
+				&dd->pcidev->dev, PAGE_SIZE,
+				&rcd->rcvhdrqtailaddr_dma, gfp_flags);
 			if (!rcd->rcvhdrtail_kvaddr)
 				goto bail_free;
-			rcd->rcvhdrqtailaddr_dma = dma_hdrqtail;
 		}
 
 		rcd->rcvhdrq_size = amt;