Commit 95154990 authored by Souptick Joarder's avatar Souptick Joarder Committed by Greg Kroah-Hartman
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staging: kpc2000: kpc_dma: Remove additional goto statements 



As 3 goto level referring to same common code, those can be
accomodated with a single goto level and renameing it to
unpin_pages. Set the -ERRNO when returning partial mapped
pages in more appropriate place.

When dma_map_sg() failed, the previously allocated memory was
not freed properly. This is corrected now.

Signed-off-by: default avatarSouptick Joarder <jrdr.linux@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Bharath Vedartham <linux.bhar@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/1593584264-16982-5-git-send-email-jrdr.linux@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ab7abbca

drivers/staging/kpc2000/kpc_dma/fileops.c

+13 −12
Original line number Diff line number Diff line
@@ -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;

	int rv = 0;

	int rv = 0, nr_pages = 0;

	struct kpc_dma_device *ldev;

	struct aio_cb_data *acd;

	DECLARE_COMPLETION_ONSTACK(done);
@@ -79,22 +79,27 @@ static int kpc_dma_transfer(struct dev_private_data *priv, 
	rv = pin_user_pages(iov_base, acd->page_count, FOLL_TOUCH | FOLL_WRITE, acd->user_pages, NULL);

	mmap_read_unlock(current->mm);        /*  release the semaphore */

	if (rv != acd->page_count) {

		nr_pages = rv;

		if (rv > 0)

			rv = -EFAULT;



		dev_err(&priv->ldev->pldev->dev, "Couldn't pin_user_pages (%d)\n", rv);

		goto err_get_user_pages;

		goto unpin_pages;

	}

	nr_pages = acd->page_count;



	// 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 (%d)\n", rv);

		goto err_alloc_sg_table;

		goto unpin_pages;

	}



	// Setup the DMA mapping for all the sg entries

	acd->mapped_entry_count = dma_map_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);

	if (acd->mapped_entry_count <= 0) {

		dev_err(&priv->ldev->pldev->dev, "Couldn't dma_map_sg (%d)\n", acd->mapped_entry_count);

		goto err_dma_map_sg;

		goto free_table;

	}



	// Calculate how many descriptors are actually needed for this transfer.
@@ -186,16 +191,12 @@ static int kpc_dma_transfer(struct dev_private_data *priv, 
 err_descr_too_many:

	unlock_engine(ldev);

	dma_unmap_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);

 free_table:

	sg_free_table(&acd->sgt);

 err_dma_map_sg:

 err_alloc_sg_table:

	unpin_user_pages(acd->user_pages, acd->page_count);



 err_get_user_pages:

	if (rv > 0) {

		unpin_user_pages(acd->user_pages, rv);

		rv = -EFAULT;

	}

 unpin_pages:

	if (nr_pages > 0)

		unpin_user_pages(acd->user_pages, nr_pages);

	kfree(acd->user_pages);

 err_alloc_userpages:

	kfree(acd);

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