Re: [Qemu-devel] [PATCH] linux-user: Emulate SOCK_CLOEXEC/NONBLOCK if unavailable

[Edgar E. Iglesias]

On Mon, Sep 23, 2013 at 12:37:10PM +0300, Riku Voipio wrote:
> Hi,

Hi Riku,

> 
> On Mon, Sep 16, 2013 at 03:08:06PM +0200, address@hidden wrote:
> > From: "Edgar E. Iglesias" <address@hidden>
> > 
> > If the host lacks support for SOCK_CLOEXEC or SOCK_NONBLOCK,
> > try to emulate them with fcntl() FD_CLOEXEC and O_NONBLOCK.
> 
> Last time emulating CLOEXEC with fcntl was discussed, the idea
> was rejected[1]. The whole point of CLOEXEC flag is guarantee
> race free open, which when implemented this way it is no longer.
> 
> It is better to tell the userspace that atomic operation is not
> available and let the userspace app/library to cope with that,
> than give the application false sense of safety.

Agreed, I'll send a v2 that EINVALs on lack of SOCK_CLOEXEC.
My primary concern is to avoid the build error of qemu.

Thanks,
Edgar