KEYS: fix in-kernel documentation for keyctl_read()

When keyctl_read() is passed a buffer that is too small, the behavior is
inconsistent.  Some key types will fill as much of the buffer as
possible, while others won't copy anything.  Moreover, the in-kernel
documentation contradicted the man page on this point.

Update the in-kernel documentation to say that this point is
unspecified.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
Eric Biggers 2017-11-15 16:38:44 +00:00 committed by David Howells
parent 37cb8e1f8e
commit be543dd626

View File

@ -628,12 +628,12 @@ The keyctl syscall functions are:
defined key type will return its data as is. If a key type does not
implement this function, error EOPNOTSUPP will result.
As much of the data as can be fitted into the buffer will be copied to
userspace if the buffer pointer is not NULL.
On a successful return, the function will always return the amount of data
available rather than the amount copied.
If the specified buffer is too small, then the size of the buffer required
will be returned. Note that in this case, the contents of the buffer may
have been overwritten in some undefined way.
Otherwise, on success, the function will return the amount of data copied
into the buffer.
* Instantiate a partially constructed key::