[PATCH AUTOSEL 5.1 108/141] nvme-pci: check for NULL return from pci_alloc_p2pmem()

Sasha Levin
2019-07-19T04:28:51Z

From: Alan Mikhak <alan.mikhak@sifive.com>

[ Upstream commit bfac8e9f55cf62a000b643a0081488badbe92d96 ]

Modify nvme_alloc_sq_cmds() to call pci_free_p2pmem() to free the memory
it allocated using pci_alloc_p2pmem() in case pci_p2pmem_virt_to_bus()
returns null.

Makes sure not to call pci_free_p2pmem() if pci_alloc_p2pmem() returned
NULL, which can happen if CONFIG_PCI_P2PDMA is not configured.

The current implementation is not expected to leak since
pci_p2pmem_virt_to_bus() is expected to fail only if pci_alloc_p2pmem()
returns null. However, checking the return value of pci_alloc_p2pmem()
is more explicit.

Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/pci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 693f2a856200..b97ba5ea0e61 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1471,11 +1471,15 @@ static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,

if (qid && dev->cmb_use_sqes && (dev->cmbsz & NVME_CMBSZ_SQS)) {
nvmeq->sq_cmds = pci_alloc_p2pmem(pdev, SQ_SIZE(depth));
- nvmeq->sq_dma_addr = pci_p2pmem_virt_to_bus(pdev,
- nvmeq->sq_cmds);
- if (nvmeq->sq_dma_addr) {
- set_bit(NVMEQ_SQ_CMB, &nvmeq->flags);
- return 0;
+ if (nvmeq->sq_cmds) {
+ nvmeq->sq_dma_addr = pci_p2pmem_virt_to_bus(pdev,
+ nvmeq->sq_cmds);
+ if (nvmeq->sq_dma_addr) {
+ set_bit(NVMEQ_SQ_CMB, &nvmeq->flags);
+ return 0;
+ }
+
+ pci_free_p2pmem(pdev, nvmeq->sq_cmds, SQ_SIZE(depth));
}
}

--
2.20.1