sh: intc: Replace simple_strtoul() with kstrtoul()

The function simple_strtoul() performs no error checking
in scenarios where the input value overflows the intended
output variable.

We can replace the use of simple_strtoul() with the safer
alternative kstrtoul(). This also allows us to print an
error message in case of failure.

Signed-off-by: Hongbo Li <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: John Paul Adrian Glaubitz <[email protected]>
Signed-off-by: John Paul Adrian Glaubitz <[email protected]>

Author: Hongbo Li

drivers/sh/intc/userimask.c

@@ -32,8 +32,11 @@ store_intc_userimask(struct device *dev,
 		     const char *buf, size_t count)
 {
 	unsigned long level;
+	int ret;
 
-	level = simple_strtoul(buf, NULL, 10);
+	ret = kstrtoul(buf, 10, &level);
+	if (ret != 0)
+		return ret;
 
 	/*
 	 * Minimal acceptable IRQ levels are in the 2 - 16 range, but