drivers/of/overlay: Use memcpy() to copy known length strings

Avoid calls to strcpy().
The lengths of the strings have been used for the kzalloc(), replace the strcpy() calls with memcpy() using the known lengths.

---

v2: Improve commit message

This is one of a group of patches that remove potentially unbounded strcpy() calls.

They are mostly replaced by strscpy() or, when strlen() has just been called, with memcpy() (usually including the '\0').

Calls with copy string literals into arrays are left unchanged. They are safe and easily detected as such.

The changes were made by getting the compiler to detect the calls and then fixing the code by hand.

Note that all the changes are only compile tested.

Some Makefiles were changed to allow files to contain strcpy(). As well as 'difficult to fix' files, this included 'show' functions as they really need to use sysfs_emit() or seq_printf().

All the patches are being sent individually to avoid very long cc lists. Apologies for the terse commit messages and likely unexpected tags. (There are about 100 patches in total.)

 drivers/of/overlay.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index c1c5686fc7b1..656867009514 100644
@@ -258,8 +258,8 @@ static struct property *dup_and_fixup_symbol_prop(
 	if (!new_prop->name || !new_prop->value)
 		goto err_free_new_prop;
 
-	strcpy(new_prop->value, target_path);
-	strcpy(new_prop->value + target_path_len, path_tail);
+	memcpy(new_prop->value, target_path, target_path_len);
+	memcpy(new_prop->value + target_path_len, path_tail, path_tail_len);
 
 	of_property_set_flag(new_prop, OF_DYNAMIC);
 

2.39.5

Applied, thanks!