Re: [Qemu-devel] [PATCH 2/3] XXX oslib-posix: Ignore fcntl("/dev/null", F_SETFL, O_NONBLOCK) failure

["Alex Bennée" <alex.bennee@linaro.org>]

Philippe Mathieu-Daudé <philmd@redhat.com> writes:

> Previous to OpenBSD 6.3 [1], fcntl(F_SETFL) is not permitted on memory
> devices. Do not assert fcntl failures on OpenBSD.
> This fixes:
>
>   $ lm32-softmmu/qemu-system-lm32
>   assertion "f != -1" failed: file "util/oslib-posix.c", line 247, function "qemu_set_nonblock"
>   Abort trap (core dumped)
>
> [1] The fix seems https://github.com/openbsd/src/commit/c2a35b387f9d3c
>   "fcntl(F_SETFL) invokes the FIONBIO and FIOASYNC ioctls internally, so
>   the memory devices (/dev/null, /dev/zero, etc) need to permit them."

I assume set_nonblock is called on more than just these special devices?
Is there anyway to check this on OpenBSD or is it just an anonymous fd
at this point?

>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  util/oslib-posix.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index 4ce1ba9ca4..064c3ae2f7 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -244,7 +244,9 @@ void qemu_set_nonblock(int fd)
>      f = fcntl(fd, F_GETFL);
>      assert(f != -1);
>      f = fcntl(fd, F_SETFL, f | O_NONBLOCK);
> +#ifndef __OpenBSD__
>      assert(f != -1);
> +#endif
>  }
>
>  int socket_set_fast_reuse(int fd)


--
Alex Bennée