[PATCH clk v2] clk: clkdev: add error messages for name exceeding maximum length

[Duanqiang Wen]

if one device register clkdev with dev_id or con_id
greater than maximum length, clkdev_create functions
will not return err, but clk_find functions will not
match the device, it's difficult to identify issues
for developers.So add error messages for dev_id greater
than 20 characters and con_id greater than 16 characters.

eg. clkdev_create(clk, NULL, "i2c_designware.16796")
it will create clk_lookup with dev_id "i2c_designware.1679",
because clk_name exceeds dev_id maximum, but clkdev_create not
return err. when driver call clk_find functions, use "i2c_desig
nware.16796" to find clk, it will return failed,but I don't know
where the problem is. It took a long time to find the problem.

Signed-off-by: Duanqiang Wen <duanqiangwen@xxxxxxxxxxxxx>
---
 drivers/clk/clkdev.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index ee37d0be6877..2d24ea232dc7 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -165,11 +165,21 @@ vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
 
 	cla->cl.clk_hw = hw;
 	if (con_id) {
+		if (strlen(dev_fmt) >= MAX_CON_ID) {
+			pr_err("%s:con_id cannot be greater than %d characters\n",
+					dev_fmt, MAX_CON_ID);
+			return NULL;
+		}
 		strscpy(cla->con_id, con_id, sizeof(cla->con_id));
 		cla->cl.con_id = cla->con_id;
 	}
 
 	if (dev_fmt) {
+		if (strlen(dev_fmt) >= MAX_DEV_ID) {
+			pr_err("%s:dev_id cannot be greater than %d characters\n",
+					dev_fmt, MAX_DEV_ID);
+			return NULL;
+		}
 		vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
 		cla->cl.dev_id = cla->dev_id;
 	}
-- 
2.27.0