* Jiachen Zhang (zhangjiachen.jaycee@bytedance.com) wrote:
> This is a work around. The qsort function will malloc memory instead of use
> stack memory when the resubmit_num is larger than 64 (total size larger than
> 1024 Bytes). This will cause seccomp kill virtiofsd, so we comment qsort.
> This work around will not affect the correctness of inflight I/O tracking.
>
> Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
That's an odd hack! Just follow the audit log to see what seccomp was
upset by and add the right syscall.
Dave
We recently found the cause is sysinfo (2). We will revert this and add sysinfo to the
whitelist in the 2nd version patchset. Thanks!
Jiachen
> ---
> contrib/libvhost-user/libvhost-user.c | 18 ------------------
> 1 file changed, 18 deletions(-)
>
> diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> index 8c97013e59..c226d5d915 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -1167,20 +1167,6 @@ vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
> return true;
> }
>
> -static int
> -inflight_desc_compare(const void *a, const void *b)
> -{
> - VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
> - *desc1 = (VuVirtqInflightDesc *)b;
> -
> - if (desc1->counter > desc0->counter &&
> - (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
> - return 1;
> - }
> -
> - return -1;
> -}
> -
> static int
> vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
> {
> @@ -1236,10 +1222,6 @@ vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
> }
> }
>
> - if (vq->resubmit_num > 1) {
> - qsort(vq->resubmit_list, vq->resubmit_num,
> - sizeof(VuVirtqInflightDesc), inflight_desc_compare);
> - }
> vq->counter = vq->resubmit_list[0].counter + 1;
> }
>
> --
> 2.20.1
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK