Re: [PATCH 124/190] Revert "spi : spi-topcliff-pch: Fix to handle empty DMA buffers"

Greg Kroah-Hartman
2021-04-27T17:33:38Z

On Wed, Apr 21, 2021 at 02:59:59PM +0200, Greg Kroah-Hartman wrote:
> This reverts commit f37d8e67f39e6d3eaf4cc5471e8a3d21209843c6.
>
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes. The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
>
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix. Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
>
> Cc: Aditya Pakki <pakki001@umn.edu>
> Cc: Mark Brown <broonie@kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> drivers/spi/spi-topcliff-pch.c | 15 ++-------------
> 1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
> index b459e369079f..12d749e9436b 100644
> --- a/drivers/spi/spi-topcliff-pch.c
> +++ b/drivers/spi/spi-topcliff-pch.c
> @@ -1290,27 +1290,18 @@ static void pch_free_dma_buf(struct pch_spi_board_data *board_dat,
> dma->rx_buf_virt, dma->rx_buf_dma);
> }
>
> -static int pch_alloc_dma_buf(struct pch_spi_board_data *board_dat,
> +static void pch_alloc_dma_buf(struct pch_spi_board_data *board_dat,
> struct pch_spi_data *data)
> {
> struct pch_spi_dma_ctrl *dma;
> - int ret;
>
> dma = &data->dma;
> - ret = 0;
> /* Get Consistent memory for Tx DMA */
> dma->tx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
> PCH_BUF_SIZE, &dma->tx_buf_dma, GFP_KERNEL);
> - if (!dma->tx_buf_virt)
> - ret = -ENOMEM;
> -
> /* Get Consistent memory for Rx DMA */
> dma->rx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
> PCH_BUF_SIZE, &dma->rx_buf_dma, GFP_KERNEL);
> - if (!dma->rx_buf_virt)
> - ret = -ENOMEM;
> -
> - return ret;
> }
>
> static int pch_spi_pd_probe(struct platform_device *plat_dev)
> @@ -1387,9 +1378,7 @@ static int pch_spi_pd_probe(struct platform_device *plat_dev)
>
> if (use_dma) {
> dev_info(&plat_dev->dev, "Use DMA for data transfers\n");
> - ret = pch_alloc_dma_buf(board_dat, data);
> - if (ret)
> - goto err_spi_register_master;
> + pch_alloc_dma_buf(board_dat, data);
> }
>
> ret = spi_register_master(master);
> --
> 2.31.1
>

THis looks correct, so I'll drop the revert.

thanks,

greg k-h