[PATCH next] gpiolib: Replace strcpy() with memcpy()

[david.laight.linux@gmail.com]

From: David Laight <david.laight.linux@gmail.com>

The length of the string is calculated in order to allocate the correct
sized memory block, use the same length to copy the string.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
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/gpio/gpiolib.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 1e6dce430dca..74d55978e2b4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -143,13 +143,15 @@ static void desc_free_label(struct rcu_head *rh)
 static int desc_set_label(struct gpio_desc *desc, const char *label)
 {
 	struct gpio_desc_label *new = NULL, *old;
+	size_t len;
 
 	if (label) {
-		new = kzalloc_flex(*new, str, strlen(label) + 1);
+		len = strlen(label);
+		new = kzalloc_flex(*new, str, len + 1);
 		if (!new)
 			return -ENOMEM;
 
-		strcpy(new->str, label);
+		memcpy(new->str, label, len);
 	}
 
 	old = rcu_replace_pointer(desc->label, new, 1);
-- 
2.39.5