[PATCH] misc/genwqe: ensure zero initialization

From: Sebastian Ott
Date: Mon Sep 12 2016 - 14:09:53 EST



Genwqe uses dma_alloc_coherent and depends on zero initialized memory. On
one occasion it ueses an explicit memset on others it uses un-initialized
memory.

This bug was covered because some archs actually return zero initialized
memory when using dma_alloc_coherent but this is by no means guaranteed.
Simply switch to dma_zalloc_coherent.

Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
---
drivers/misc/genwqe/card_ddcb.c | 2 --
drivers/misc/genwqe/card_utils.c | 4 ++--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/genwqe/card_ddcb.c b/drivers/misc/genwqe/card_ddcb.c
index 353ee0c..ddfeefe 100644
--- a/drivers/misc/genwqe/card_ddcb.c
+++ b/drivers/misc/genwqe/card_ddcb.c
@@ -1048,8 +1048,6 @@ static int setup_ddcb_queue(struct genwqe_dev *cd, struct ddcb_queue *queue)
"[%s] **err: could not allocate DDCB **\n", __func__);
return -ENOMEM;
}
- memset(queue->ddcb_vaddr, 0, queue_size);
-
queue->ddcb_req = kzalloc(sizeof(struct ddcb_requ *) *
queue->ddcb_max, GFP_KERNEL);
if (!queue->ddcb_req) {
diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c
index 222367c..8a679ec 100644
--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -220,8 +220,8 @@ void *__genwqe_alloc_consistent(struct genwqe_dev *cd, size_t size,
if (get_order(size) > MAX_ORDER)
return NULL;

- return dma_alloc_coherent(&cd->pci_dev->dev, size, dma_handle,
- GFP_KERNEL);
+ return dma_zalloc_coherent(&cd->pci_dev->dev, size, dma_handle,
+ GFP_KERNEL);
}

void __genwqe_free_consistent(struct genwqe_dev *cd, size_t size,
--
2.5.5