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Subject[PATCH v2 1/4] staging: kpc2000: kpc_dma: Unpin partial pinned pages
Date
There is a bug, when get_user_pages() failed but partially pinned
pages are not unpinned and positive numbers are returned instead of
-ERRNO. Fixed it.

Also, int is more appropriate type for rv. Changed it.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Bharath Vedartham <linux.bhar@gmail.com>
---
drivers/staging/kpc2000/kpc_dma/fileops.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
index 8975346..becdb41 100644
--- a/drivers/staging/kpc2000/kpc_dma/fileops.c
+++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
@@ -35,7 +35,7 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
unsigned long iov_base, size_t iov_len)
{
unsigned int i = 0;
- long rv = 0;
+ int rv = 0;
struct kpc_dma_device *ldev;
struct aio_cb_data *acd;
DECLARE_COMPLETION_ONSTACK(done);
@@ -79,14 +79,14 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
rv = get_user_pages(iov_base, acd->page_count, FOLL_TOUCH | FOLL_WRITE | FOLL_GET, acd->user_pages, NULL);
mmap_read_unlock(current->mm); /* release the semaphore */
if (rv != acd->page_count) {
- dev_err(&priv->ldev->pldev->dev, "Couldn't get_user_pages (%ld)\n", rv);
+ dev_err(&priv->ldev->pldev->dev, "Couldn't get_user_pages (%d)\n", rv);
goto err_get_user_pages;
}

// Allocate and setup the sg_table (scatterlist entries)
rv = sg_alloc_table_from_pages(&acd->sgt, acd->user_pages, acd->page_count, iov_base & (PAGE_SIZE - 1), iov_len, GFP_KERNEL);
if (rv) {
- dev_err(&priv->ldev->pldev->dev, "Couldn't alloc sg_table (%ld)\n", rv);
+ dev_err(&priv->ldev->pldev->dev, "Couldn't alloc sg_table (%d)\n", rv);
goto err_alloc_sg_table;
}

@@ -193,10 +193,15 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
put_page(acd->user_pages[i]);

err_get_user_pages:
+ if (rv > 0) {
+ for (i = 0; i < rv; i++)
+ put_pages(acd->user_pages[i]);
+ rv = -EFAULT;
+ }
kfree(acd->user_pages);
err_alloc_userpages:
kfree(acd);
- dev_dbg(&priv->ldev->pldev->dev, "%s returning with error %ld\n", __func__, rv);
+ dev_dbg(&priv->ldev->pldev->dev, "%s returning with error %d\n", __func__, rv);
return rv;
}

--
1.9.1
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