staging/sep: Check pointers before dereferencing (fix smatch warning)

smatch complains about two dereferenced before check issues:

sep_main.c:2898 sep_free_dma_tables_and_dcb() warn: variable dereferenced before check
'dma_ctx' (see line 2885)
sep_main.c:2898 sep_free_dma_tables_and_dcb() warn: variable dereferenced before check
'*dma_ctx' (see line 2885)

-> Move the checks to the top, but keep the semantics.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/sep/sep_main.c b/drivers/staging/sep/sep_main.c
index 366d56b9a255e1691af9d1d9048da7263104e72a..f5b73419eebca6124afad538652a0c0c7ba1941b 100644 (file)
--- a/drivers/staging/sep/sep_main.c
+++ b/drivers/staging/sep/sep_main.c
@@ -2880,6 +2880,8 @@ static int sep_free_dma_tables_and_dcb(struct sep_device *sep, bool isapplet,
 
        dev_dbg(&sep->pdev->dev, "[PID%d] sep_free_dma_tables_and_dcb\n",
                                        current->pid);
+       if (!dma_ctx || !*dma_ctx) /* nothing to be done here*/
+               return 0;
 
        if (((*dma_ctx)->secure_dma == false) && (isapplet == true)) {
                dev_dbg(&sep->pdev->dev, "[PID%d] handling applet\n",
@@ -2895,8 +2897,7 @@ static int sep_free_dma_tables_and_dcb(struct sep_device *sep, bool isapplet,
                 * Go over each DCB and see if
                 * tail pointer must be updated
                 */
-               for (i = 0; dma_ctx && *dma_ctx &&
-                       i < (*dma_ctx)->nr_dcb_creat; i++, dcb_table_ptr++) {
+               for (i = 0; i < (*dma_ctx)->nr_dcb_creat; i++, dcb_table_ptr++) {
                        if (dcb_table_ptr->out_vr_tail_pt) {
                                pt_hold = (unsigned long)dcb_table_ptr->
                                        out_vr_tail_pt;