Re: [PATCH v2] kvm: Fix kvm_vm_ioctl() and kvm_device_ioctl() return value

[Markus Armbruster <armbru@redhat.com>]

Markus Armbruster <armbru@redhat.com> writes:

> These functions wrap ioctl().  When ioctl() fails, it sets @errno.
> The wrappers then return that @errno negated.
>
> Except they call accel_ioctl_end() between calling ioctl() and reading
> @errno.  accel_ioctl_end() can clobber @errno, e.g. when a futex()
> system call fails.  Seems unlikely, but it's a bug all the same.
>
> Fix by retrieving @errno before calling accel_ioctl_end().
>
> Fixes: a27dd2de68f3 (KVM: keep track of running ioctls)
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Queued for 10.2.