Re: [libvirt] [PATCH v3 4/4] qemu-config: Add new -add-fd command line option

Am 17.10.2012 06:16, schrieb Eric Blake: > I'm still seeing the corner case of: > > qemu-kvm -add-fd fd=3,set=1 -add-fd fd=4,set=2 4<&- > > where the dup(3) will populate fd 4 prior to the point where we get to > process the -add-fd fd=4 command to notice that the user started > qemu-kvm with fd 4 closed, and thus qemu will silently proceed to use > the wrong fd. > > On the other hand, I'm not sure if that corner case is worth worrying > about, or if we just chalk it up to user stupidity (aka libvirt > programmer stupidity) if they did something like that (most likely, > because the management app forgot to clear FD_CLOEXEC before exec()ing > qemu-kvm). If you specify an FD number that isn't actually open when qemu is stared, you can get any FD that qemu opens internally. I think the correct answer to this problem is "then don't do that".