bpf: Replace ARG_XXX_OR_NULL with ARG_XXX | PTR_MAYBE_NULL

mainline inclusion
from mainline-v5.17-rc1
commit 48946bd6
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4WRPV
CVE: CVE-2022-0500

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=48946bd6a5d695c50b34546864b79c1f910a33c1



--------------------------------

We have introduced a new type to make bpf_arg composable, by
reserving high bits of bpf_arg to represent flags of a type.

One of the flags is PTR_MAYBE_NULL which indicates a pointer
may be NULL. When applying this flag to an arg_type, it means
the arg can take NULL pointer. This patch switches the
qualified arg_types to use this flag. The arg_types changed
in this patch include:

1. ARG_PTR_TO_MAP_VALUE_OR_NULL
2. ARG_PTR_TO_MEM_OR_NULL
3. ARG_PTR_TO_CTX_OR_NULL
4. ARG_PTR_TO_SOCKET_OR_NULL
5. ARG_PTR_TO_ALLOC_MEM_OR_NULL
6. ARG_PTR_TO_STACK_OR_NULL

This patch does not eliminate the use of these arg_types, instead
it makes them an alias to the 'ARG_XXX | PTR_MAYBE_NULL'.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-3-haoluo@google.com


Conflicts:
	include/linux/bpf.h
	kernel/bpf/verifier.c
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Reviewed-by: Kuohai Xu <xukuohai@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>