linux/tools
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
..
accounting
arch tools arch x86: Sync asm/cpufeatures.h with the kernel sources 2019-12-02 15:20:05 -03:00
bpf bpftool: Add misc section and probe for large INSN limit 2020-01-08 19:34:45 +01:00
build perf tools: Allow to link with libbpf dynamicaly 2019-11-26 11:17:45 -03:00
cgroup iocost_monitor: Report debt 2019-09-10 12:31:39 -06:00
debugging
firewire
firmware
gpio tools: gpio: Correctly add make dependencies for gpio_utils 2019-11-13 13:46:04 +01:00
hv tools: hv: add vmbus testing tool 2019-11-21 20:10:44 -05:00
iio tools: iio: Correctly add make dependency for iio_utils 2019-11-10 17:11:06 +00:00
include bpf: Document BPF_F_QUERY_EFFECTIVE flag 2020-01-09 09:40:06 -08:00
io_uring
kvm/kvm_stat
laptop
leds
lib bpf: libbpf: Add STRUCT_OPS support 2020-01-09 08:46:18 -08:00
memory-model tools/memory-model/Documentation: Add plain accesses and data races to explanation.txt 2019-10-05 11:59:44 -07:00
nfsd
objtool Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 15:04:47 -08:00
pci tools: PCI: Fix fd leakage 2019-10-29 12:04:18 +00:00
pcmcia
perf perf vendor events s390: Remove name from L1D_RO_EXCL_WRITES description 2019-12-16 13:40:26 -03:00
power platform-drivers-x86 for v5.5-1 2019-12-01 18:24:25 -08:00
scripts
spi
testing bpf: Add bpf_dctcp example 2020-01-09 08:46:18 -08:00
thermal/tmon
time
usb usbip: tools: fix fd leakage in the function of read_attr_usbip_status 2019-11-07 11:25:01 +01:00
virtio tools/virtio: xen stub 2019-10-13 09:38:27 -04:00
vm
wmi
Makefile