Re: [Qemu-devel] [PATCH] memfd: fix configure test

[Florian Weimer]

On 11/28/2017 12:42 PM, Marc-André Lureau wrote:

> Couldn't the declarations be put in sys/memfd.h like the man claimed
> it would be for > 1y?

We discussed it.  It was a typo in the manual page.  There never was a 
<sys/memfd.h> header file:

  https://marc.info/?l=linux-man&m=150988359906012&w=2

The UAPI header is called <linux/memfd.h>.

The downside of using a separate header is that you cannot determine, 
using the preprocessor alone, whether the toolchain provides the 
memfd_create function.  If we put everything in <sys/mman.h>, you can 
use “#ifdef MFD_CLOEXEC” to see if the definitions and declarations are 
there.

Thanks,
Florian