Re: [patch] mremap.2: Add description of old_size == 0 functionality
From: Mike Kravetz
Date: Mon Sep 18 2017 - 13:22:16 EST
On 09/17/2017 06:52 PM, Jann Horn wrote:
> 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
>> .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"?
Yes that is wrong. In addition, the description of this functionality
in the section before this is also incorrect.
I will fix both in a new version of the patch.