mtd: nand: Error out if cmd_ctrl() is missing
If no user specified chip->select_chip() function is provided, code in
nand_base.c will automatically set this hook to nand_select_chip(),
which in turn depends on chip->cmd_ctrl() hook being valid. Not
providing both of those functions in NAND controller driver (for example
by mistake) will result in a bit cryptic segfault. Same is true for
chip->cmdfunc().
To avoid the above scenario add a check in nand_scan_dent and error out
if cmd_ctrl() is not provided.
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Suggested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 53ea796..7f742c9 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4140,6 +4140,15 @@
if (!mtd->name && mtd->dev.parent)
mtd->name = dev_name(mtd->dev.parent);
+ if ((!chip->cmdfunc || !chip->select_chip) && !chip->cmd_ctrl) {
+ /*
+ * Default functions assigned for chip_select() and
+ * cmdfunc() both expect cmd_ctrl() to be populated,
+ * so we need to check that that's the case
+ */
+ pr_err("chip.cmd_ctrl() callback is not provided");
+ return -EINVAL;
+ }
/* Set the default functions */
nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);