mtd: sa1100: avoid VLA in sa1100_setup_mtd

Enabling -Wvla found another variable-length array with randconfig
testing:

drivers/mtd/maps/sa1100-flash.c: In function 'sa1100_setup_mtd':
drivers/mtd/maps/sa1100-flash.c:224:10: error: ISO C90 forbids variable length array 'cdev' [-Werror=vla]

Dynamically allocate the cdev array passed to mtd_concat_create()
instead of using a VLA.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Olof Johansson <olof@lixom.net>

diff --git a/drivers/mtd/maps/sa1100-flash.c b/drivers/mtd/maps/sa1100-flash.c
index 784c6e1a0391e92c90723e698d8bc148fe3e4916..fd5fe12d74613ecebddb88699dcae5e1862d3829 100644 (file)
--- a/drivers/mtd/maps/sa1100-flash.c
+++ b/drivers/mtd/maps/sa1100-flash.c
@@ -221,7 +221,14 @@ static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
                info->mtd = info->subdev[0].mtd;
                ret = 0;
        } else if (info->num_subdev > 1) {
-               struct mtd_info *cdev[nr];
+               struct mtd_info **cdev;
+
+               cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
+               if (!cdev) {
+                       ret = -ENOMEM;
+                       goto err;
+               }
+
                /*
                 * We detected multiple devices.  Concatenate them together.
                 */
@@ -230,6 +237,7 @@ static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
 
                info->mtd = mtd_concat_create(cdev, info->num_subdev,
                                              plat->name);
+               kfree(cdev);
                if (info->mtd == NULL) {
                        ret = -ENXIO;
                        goto err;