In preparation to enabling -Wvla, remove VLAs and replace them with fixed-length arrays instead. rtc-mcp795.c uses a variable-length array declaration to contain the command to write the rtcc; this can be replaced by a fixed- size array of length 2 (instruction, address) + 32 (data out), assuming a maximum data length of 32 bytes before wrap up. This was prompted by https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Stefano Manni <stefano.manni@xxxxxxxxx> --- drivers/rtc/rtc-mcp795.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c index 77f21331ae21..a5f504e2364c 100644 --- a/drivers/rtc/rtc-mcp795.c +++ b/drivers/rtc/rtc-mcp795.c @@ -61,6 +61,9 @@ #define SEC_PER_DAY (24 * 60 * 60) +/* Maximum length for data out in write operation to RTCC */ +#define MCP795_MAX_DATAOUT_LEN 32 + static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count) { struct spi_device *spi = to_spi_device(dev); @@ -82,7 +85,10 @@ static int mcp795_rtcc_write(struct device *dev, u8 addr, u8 *data, u8 count) { struct spi_device *spi = to_spi_device(dev); int ret; - u8 tx[2 + count]; + u8 tx[2 + MCP795_MAX_DATAOUT_LEN]; + + if (count > MCP795_MAX_DATAOUT_LEN) + return -EINVAL; tx[0] = MCP795_WRITE; tx[1] = addr; -- 2.14.3
