Re: [PATCH 3/4] char/tpm: Improve a size determination in nine functions

On Tue, 2017-10-17 at 14:58 +0200, Julia Lawall wrote:

On Tue, 17 Oct 2017, Mimi Zohar wrote:

quoted

On Tue, 2017-10-17 at 11:50 +0000, Alexander.Steffen@infineon.com
wrote:

quoted

quoted

quoted

Replace the specification of data structures by pointer dereferences
as the parameter for the operator "sizeof" to make the corresponding
size
determination a bit safer according to the Linux coding style
convention.

This patch does one style in favor of the other.

I actually prefer that style, so I'd welcome this change :)

Style changes should be reviewed and documented, like any other code
change, and added to Documentation/process/coding-style.rst or an
equivalent file.

Actually, it has been there for many years:

14) Allocating memory
---------------------
...
The preferred form for passing a size of a struct is the following:

.. code-block:: c

	p = kmalloc(sizeof(*p), ...);

The alternative form where struct name is spelled out hurts readability and
introduces an opportunity for a bug when the pointer variable type is changed
but the corresponding sizeof that is passed to a memory allocator is not.

True, thanks for the reminder.  Is this common in new code?  Is there
a script/ or some other automated way of catching this usage before
patches are upstreamed?

Just as you're doing here, the patch description should reference this
in the patch description.

Mimi