Re: [PATCH 41/82] wil6210: Refactor intentional wrap-around test

Kees Cook [off-list ref] writes:

In an effort to separate intentional arithmetic wrap-around from
unexpected wrap-around, we need to refactor places that depend on this
kind of math. One of the most common code patterns of this is:

	VAR + value < VAR

Notably, this is considered "undefined behavior" for signed and pointer
types, which the kernel works around by using the -fno-strict-overflow
option in the build[1] (which used to just be -fwrapv). Regardless, we
want to get the kernel source to the position where we can meaningfully
instrument arithmetic wrap-around conditions and catch them when they
are unexpected, regardless of whether they are signed[2], unsigned[3],
or pointer[4] types.

Refactor open-coded wrap-around addition test to use add_would_overflow().
This paves the way to enabling the wrap-around sanitizers in the future.

Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594 [1]
Link: https://github.com/KSPP/linux/issues/26 [2]
Link: https://github.com/KSPP/linux/issues/27 [3]
Link: https://github.com/KSPP/linux/issues/344 [4]
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Johannes Berg <redacted>
Cc: Max Chen <redacted>
Cc: Yang Shen <shenyang39@huawei.com>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Kees Cook <redacted>

I assume this goes via some other tree than wireless-next so:

Acked-by: Kalle Valo <kvalo@kernel.org>

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