CodingStyle: Clarify and complete chapter 7

cleanup needed then just return directly.

Choose label names which say what the goto does or why the goto exists.  An

example of a good name could be "out_buffer:" if the goto frees "buffer".  Avoid

using GW-BASIC names like "err1:" and "err2:".  Also don't name them after the

goto location like "err_kmalloc_failed:"

example of a good name could be "out_free_buffer:" if the goto frees "buffer".

Avoid using GW-BASIC names like "err1:" and "err2:", as you would have to

renumber them if you ever add or remove exit paths, and they make correctness

difficult to verify anyway.

It is advised to indent labels with a single space (not tab), so that

"diff -p" does not confuse labels with functions.

The rationale for using gotos is:

			goto out_buffer;

		}

		...

	out_buffer:

	 out_free_buffer:

		kfree(buffer);

		return result;

	}

		return ret;

The bug in this code is that on some exit paths "foo" is NULL.  Normally the

fix for this is to split it up into two error labels "err_bar:" and "err_foo:".

fix for this is to split it up into two error labels "err_free_bar:" and

"err_free_foo:":

	 err_free_bar:

		kfree(foo->bar);

	 err_free_foo:

		kfree(foo);

		return ret;

Ideally you should simulate errors to test all exit paths.

		Chapter 8: Commenting