From: David Howells <dhowe...@redhat.com> Date: Mon, 06 Mar 2017 15:04:44 +0000
> Fix the general case by: > > (1) Double up all the locking keys used in sockets so that one set are > used if the socket is created by userspace and the other set is used > if the socket is created by the kernel. > > (2) Store the kern parameter passed to sk_alloc() in a variable in the > sock struct (sk_kern_sock). This informs sock_lock_init(), > sock_init_data() and sk_clone_lock() as to the lock keys to be used. > > Note that the child created by sk_clone_lock() inherits the parent's > kern setting. > > (3) Add a 'kern' parameter to ->accept() that is analogous to the one > passed in to ->create() that distinguishes whether kernel_accept() or > sys_accept4() was the caller and can be passed to sk_alloc(). > > Note that a lot of accept functions merely dequeue an already > allocated socket. I haven't touched these as the new socket already > exists before we get the parameter. > > Note also that there are a couple of places where I've made the accepted > socket unconditionally kernel-based: > > irda_accept() > rds_rcp_accept_one() > tcp_accept_from_sock() > > because they follow a sock_create_kern() and accept off of that. I guess this is fine, but I think you can use one of the two "sk_padding" bits in struct sock instead of making the structure larger.
