mainline inclusion
from mainline-5.14-rc1
commit d6a6a555
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=d6a6a55518c16040a369360255b355b7a2a261de

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

These macros are convenient wrappers around the bpf_seq_printf and
bpf_snprintf helpers. They are currently provided by bpf_tracing.h which
targets low level tracing primitives. bpf_helpers.h is a better fit.

The __bpf_narg and __bpf_apply are needed in both files and provided
twice. __bpf_empty isn't used anywhere and is removed from bpf_tracing.h
Reported-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NFlorent Revest <revest@chromium.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210526164643.2881368-1-revest@chromium.org
(cherry picked from commit d6a6a555)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

Conflicts:
	tools/testing/selftests/bpf/progs/bpf_iter_task_vma.c
	tools/testing/selftests/bpf/progs/test_snprintf.c
Signed-off-by: NWang Yufen <wangyufen@huawei.com>