"Denis V. Lunev" <den@xxxxxxxxxx> writes: > This patch reverts Eric's commit 2b008b0a8e96b726c603c5e1a5a7a509b5f61e35 > > It diets .text & .data section of the kernel if CONFIG_NET_NS is not set. > This is safe after list operations cleanup. Ok. This patch is technically safe because none of the touched code can live in a module and so we never touch the exit code path. However in the general case and as a code idiom this __net_initdata on struct pernet_operations is fundamentally horribly broken. Look at what happens if we use this idiom in module. There is only one definition of __initdata ".init.data". The module loader places all sections that begin with .init in a region of memory that will be discarded after module initialization. So in register_pernet_operations we pass in the a pointer to struct pernet_operations and call the init method. Later when we remove the module we again pass in the pointer to struct pernet_operations which lived in an init section so it has been discarded. We dereference that pointer to find the exit method and KABOOM!!!! So I'm still opposed to __net_initdata on the grounds that at best it is like putting our head under a guillotine and reaching up and sawing at the row that holds the blade up with a pocket knife. It is a think rope and a puny knife so you are safe for a while.... Eric _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
