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Re: [PATCH RFC] Add support for linux memfd_create syscall
- From: David Herrmann <dh dot herrmann at gmail dot com>
- To: "Carlos O'Donell" <carlos at redhat dot com>
- Cc: libc-alpha at sourceware dot org
- Date: Fri, 21 Nov 2014 19:26:02 +0100
- Subject: Re: [PATCH RFC] Add support for linux memfd_create syscall
- Authentication-results: sourceware.org; auth=none
- References: <1413537694-30556-1-git-send-email-dh dot herrmann at gmail dot com> <546F808C dot 1070801 at redhat dot com>
On Fri, Nov 21, 2014 at 7:12 PM, Carlos O'Donell <firstname.lastname@example.org> wrote:
> On 10/17/2014 05:21 AM, David Herrmann wrote:
>> The memfd_create() syscall was released with linux-3.17. It's a linux-only
>> syscall and returns a shmem file-descriptor backed by anonymous memory
>> in a kernel-internal shmem mount.
> In general I'm trying hard to make this kind of patch easy to accept.
> See the WIP consensus here:
> In order to get your patch accepted you have answer some implicit
> questions like "How do users use it?" "Why do users need it?"
Sure, will add that in v2.
> From a high-level perspective your patch is missing:
> - A test case if possible with non-root privs, or an xcheck test if root
> is required.
> e.g. ./sysdeps/unix/sysv/linux/tst-memfd_create.c
I already wrote extensive tests which are included in the kernel. I
will try to extract a sensible part and put it into glibc.
> - Documentation for the manual covering the use of the function.
> e.g. ./manual/llio.texi, new section under low-level IO, and specify
> that it is Linux specific. Feel free to submit your own text to the
> linux-kernel man pages to get a new man page created.
My kernel patches already had man-pages included. I'm currently
talking with Michael Kerrisk to get them upstream. I will try to
include something for llio.texi in v2.
> Lastly you'll want to review:
> The present patch is mechanical in nature and doesn't require copyright
> assignment, but adding the test case, and manual entry brings you into
> legally significant territory. Do you have a copyright assignment with
> the FSF for glibc?
I remember someone telling me RedHat had a copyright agreement with
the FSF, but the link explicitly states you need it from the _author_.
I will send v2 as 2 patches, if you consider either a non-mechanical
contribution, we will have to delay it until my copyright agreement
with the FSF is done.