Re: [patch] mremap.2: Add description of old_size == 0 functionality

[Jann Horn]

On Fri, Sep 15, 2017 at 2:37 PM, Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote:
[...]
> A recent change was made to mremap so that an attempt to create a
> duplicate a private mapping will fail.
>
> commit dba58d3b8c5045ad89c1c95d33d01451e3964db7
> Author: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> Date:   Wed Sep 6 16:20:55 2017 -0700
>
>     mm/mremap: fail map duplication attempts for private mappings
>
> This return code is also documented here.
[...]
> diff --git a/man2/mremap.2 b/man2/mremap.2
[...]
> @@ -174,7 +189,12 @@ and
>  or
>  .B MREMAP_FIXED
>  was specified without also specifying
> -.BR MREMAP_MAYMOVE .
> +.BR MREMAP_MAYMOVE ;
> +or \fIold_size\fP was zero and \fIold_address\fP does not refer to a
> +private anonymous mapping;

Shouldn't this be the other way around? "or old_size was zero and
old_address refers to a private anonymous mapping"?