Re: git: 2c24ad3377a6 - main - ifconfig: abort if loading a module fails other than for ENOENT
Date: Fri, 20 Jan 2023 17:12:52 UTC
On Fri, Jan 20, 2023 at 9:49 AM Gleb Smirnoff <glebius@freebsd.org> wrote: > > On Fri, Jan 20, 2023 at 11:04:33AM +0000, Alexander Chernikov wrote: > A> I think another question is that if if should be done by ifconfig(8) at all. Kernel can take care of trying to load the required modules, checking the privileges. > A> I’m considering adding such code for the netlink-based interface creation. > > This is already done in netgraph, but I won't call this solution a > pretty one. You ask kernel to do some network related ioctl(2), but > it actually does kldload(2). > > At what stage of the syscall we understand that kldload(2) needs to > be done? Are we free of network locks at this stage? Cause kldload > will take a very different set of locks, possibly creating a LOR, > and in an edge case will go into NFS taking network locks. > > -- > Gleb Smirnoff ifconfig tries to load a KLD preemptively, long before it does the hard work (cloning an interface or something). Trying to teach the kernel to load the module on-demand would be hard, we would probably have to do it in many different places.