There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member instead of a one-element array. Also, make use of the struct_size() helper to calculate the size of the allocation for _nand_. In order to keep the code as maintainable as possible and to keep _cs_ as an array, add a new macro CS_N to aid in the allocation size calculation, in case there is a need for more Chip Select IDs in the future. In the meantime, the macro is set to 1. This also avoids having to use a magic number '1' as the last argument for struct_size(). [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Build-tested-by: kernel test robot <lkp@xxxxxxxxx> Link: https://lore.kernel.org/lkml/5f7473c0.Vv4h6yzXSga90P04%25lkp@xxxxxxxxx/ Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> --- drivers/mtd/nand/raw/tegra_nand.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/nand/raw/tegra_nand.c b/drivers/mtd/nand/raw/tegra_nand.c index fbf67722a049..43b8359dcd85 100644 --- a/drivers/mtd/nand/raw/tegra_nand.c +++ b/drivers/mtd/nand/raw/tegra_nand.c @@ -163,6 +163,9 @@ HWSTATUS_RBSY_MASK(NAND_STATUS_READY) | \ HWSTATUS_RBSY_VALUE(NAND_STATUS_READY)) +/* Number of Chip Selects. Currently, only one. */ +#define CS_N 1 + struct tegra_nand_controller { struct nand_controller controller; struct device *dev; @@ -183,7 +186,7 @@ struct tegra_nand_chip { u32 config; u32 config_ecc; u32 bch_config; - int cs[1]; + int cs[]; }; static inline struct tegra_nand_controller * @@ -1086,14 +1089,14 @@ static int tegra_nand_chips_init(struct device *dev, return -EINVAL; } - /* Retrieve CS id, currently only single die NAND supported */ + /* Retrieve CS id, currently only single-die NAND supported */ ret = of_property_read_u32(np_nand, "reg", &cs); if (ret) { dev_err(dev, "could not retrieve reg property: %d\n", ret); return ret; } - nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL); + nand = devm_kzalloc(dev, struct_size(nand, cs, CS_N), GFP_KERNEL); if (!nand) return -ENOMEM; -- 2.27.0
