Now that Linux 5.8 is in the stablization phase it makes sense to support compiling against it.
There are several changes that we need to adjust for. Some are easy, some require more work.
- removes the fmr_pool API.
- doesn't use mmap_sem directly any more - use "mmap_read_lock()" and similar
- kernel_setsockopt() has gone - need to use more direct access.
- rdma_reject() needs a new "reason for reject" arg
- NR_UNSTABLE_NFS has gone. Use NR_WRITEBACK instead
- 'dummy_context' in fscrypt has changed to "get_dummy_context", and fscrypt_dummy_context is now fsctype_get_dummy_context
- unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()
- __vmalloc() now only has 2 args.
- FIELD_SIZEOF is gone, use sizeof_field
- blkcipher is gone,, use skcipher
- cached rb_tree changes
- sysctl handlers like proc_doinvec now take a kernel pointer rather than a __user pointer