bpf: Change bpf_kallsyms_lookup_name size type to ARG_CONST_SIZE_OR_ZERO

mainline inclusion
from mainline-5.17-rc1
commit d4efb170
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d4efb170861827290f7f571020001a60d001faaf

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

Andrii mentioned in [0] that switching to ARG_CONST_SIZE_OR_ZERO lets
user avoid having to prove that string size at runtime is not zero and
helps with not having to supress clang optimizations.

  [0]: https://lore.kernel.org/bpf/CAEf4BzZa_vhXB3c8atNcTS6=krQvC25H7K7c3WWZhM=27ro=Wg@mail.gmail.comSuggested-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211122235733.634914-2-memxor@gmail.com
(cherry picked from commit d4efb170)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

kernel/bpf/syscall.c

@@ -4726,7 +4726,7 @@ const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
 	.arg1_type	= ARG_PTR_TO_MEM,
-	.arg2_type	= ARG_CONST_SIZE,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
 	.arg3_type	= ARG_ANYTHING,
 	.arg4_type	= ARG_PTR_TO_LONG,
 };