Commit 3577cdb2 authored Sep 25, 2021 by Len Baker Committed by Jonathan Corbet Oct 26, 2021

docs: deprecated.rst: Clarify open-coded arithmetic with literals



Although using literals for size calculation in allocator arguments may
be harmless due to compiler warnings in case of overflows, it is better
to refactor the code to avoid the use of open-coded arithmetic.

So, clarify the preferred way in these cases.

Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20210925143455.21221-1-len.baker@gmx.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>

parent 6e74e68d

Documentation/process/deprecated.rst

+3 −2

Original line number	Diff line number	Diff line
		@@ -59,8 +59,9 @@ risk of them overflowing. This could lead to values wrapping around and a
		smaller allocation being made than the caller was expecting. Using those
		allocations could lead to linear overflows of heap memory and other
		misbehaviors. (One exception to this is literal values where the compiler
		can warn if they might overflow. Though using literals for arguments as
		suggested below is also harmless.)
		can warn if they might overflow. However, the preferred way in these
		cases is to refactor the code as suggested below to avoid the open-coded
		arithmetic.)

		For example, do not use ``count * size`` as an argument, as in::