linux-stable/include
Andrey Ignatov f5bfcd953d bpf: Document BPF_F_QUERY_EFFECTIVE flag
Document BPF_F_QUERY_EFFECTIVE flag, mostly to clarify how it affects
attach_flags what may not be obvious and what may lead to confision.

Specifically attach_flags is returned only for target_fd but if programs
are inherited from an ancestor cgroup then returned attach_flags for
current cgroup may be confusing. For example, two effective programs of
same attach_type can be returned but w/o BPF_F_ALLOW_MULTI in
attach_flags.

Simple repro:
  # bpftool c s /sys/fs/cgroup/path/to/task
  ID       AttachType      AttachFlags     Name
  # bpftool c s /sys/fs/cgroup/path/to/task effective
  ID       AttachType      AttachFlags     Name
  95043    ingress                         tw_ipt_ingress
  95048    ingress                         tw_ingress

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200108014006.938363-1-rdna@fb.com
2020-01-09 09:40:06 -08:00
..
acpi
asm-generic powerpc updates for 5.5 #2 2019-12-06 13:36:31 -08:00
clocksource
crypto
drm mm + drm coherent memory support for vmwgfx 2019-11-30 09:38:11 -08:00
dt-bindings ARM: Device-tree updates 2019-12-05 12:09:47 -08:00
keys powerpc updates for 5.5 2019-11-30 14:35:43 -08:00
kunit
kvm
linux bpf: tcp: Support tcp_congestion_ops in bpf 2020-01-09 08:46:18 -08:00
math-emu
media
misc
net bpf: tcp: Support tcp_congestion_ops in bpf 2020-01-09 08:46:18 -08:00
pcmcia
ras
rdma IB/core: Introduce rdma_user_mmap_entry_insert_range() API 2019-12-12 16:55:36 -05:00
scsi
soc net: mscc: ocelot: export ANA, DEV and QSYS registers to include/soc/mscc 2020-01-05 23:22:33 -08:00
sound ASoC: Fixes for v5.5 2019-12-17 14:18:32 +01:00
target
trace sctp: move trace_sctp_probe_path into sctp_outq_sack 2019-12-26 13:06:45 -08:00
uapi bpf: Document BPF_F_QUERY_EFFECTIVE flag 2020-01-09 09:40:06 -08:00
vdso
video
xen xen/interface: re-define FRONT/BACK_RING_ATTACH() 2019-12-20 13:44:42 +01:00