# RE: Buggy commit tracked to: "Re: \[PATCH 2/9\] iov\_iter: move rw\_copy\_check\_uvector() into lib/iov\_iter.c"

- From: David Laight \<hidden\>
- Date: 2020-10-22 22:04:11 
- List: linux-security-module
- Page: https://ratatoskr.run/linux-security-module/2020/10/191063
- Thread: https://ratatoskr.run/linux-arm-kernel/2020/10/191046/t.md

```text
From: Nick Desaulniers
> Sent: 22 October 2020 20:05
> 
...
> Passing an `unsigned long` as an `unsigned int` does no such
> narrowing: https://godbolt.org/z/TvfMxe (same vice-versa, just tail
> calls, no masking instructions).

Right but is the called function going to use 32bit ops
and/or mask the register?
Certainly that is likely on x86-64.

I've rather lost track of where the masking is expected
to happen.

	David

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```