From: Andrey Smirnov Date: Thu, 21 Jul 2016 21:59:20 +0000 (-0700) Subject: mtd: nand: Error out if cmd_ctrl() is missing X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=76fe334f71dd20f7eadd4c624441ec7d1fb92f33;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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 Suggested-by: Brian Norris Signed-off-by: Andrey Smirnov Signed-off-by: Boris Brezillon --- diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 53ea79628dde..7f742c9c9015 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -4140,6 +4140,15 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips, 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);