Re: [patch v2] mremap.2: Add description of old_size == 0 functionality

From: Michael Kerrisk (man-pages)
Date: Mon Sep 25 2017 - 08:41:28 EST


On 25 September 2017 at 14:36, Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> On Wed 20-09-17 09:25:42, Michael Kerrisk wrote:
> [...]
>> BUGS
>> Before Linux 4.14, if old_size was zero and the mapping referred
>> to by old_address was a private mapping (mmap(2) MAP_PRIVATE),
>> mremap() created a new private mapping unrelated to the original
>> mapping. This behavior was unintended and probably unexpected in
>> user-space applications (since the intention of mremap() is to
>> create a new mapping based on the original mapping). Since Linux
>> 4.14, mremap() fails with the error EINVAL in this scenario.
>>
>> Does that seem okay?
>
> sorry to be late but yes this wording makes perfect sense to me.

Thanks, Michal.

Cheers,

Michael

--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/