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author | Yonghong Song <yhs@fb.com> | 2020-05-09 19:59:05 +0200 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2020-05-10 02:05:26 +0200 |
commit | ac51d99bf81caac8d8881fe52098948110d0de68 (patch) | |
tree | 9c7545c775f20bb4e1b51a46be06af04d5f2755e /tools/include | |
parent | bpf: Implement bpf_seq_read() for bpf iterator (diff) | |
download | linux-ac51d99bf81caac8d8881fe52098948110d0de68.tar.xz linux-ac51d99bf81caac8d8881fe52098948110d0de68.zip |
bpf: Create anonymous bpf iterator
A new bpf command BPF_ITER_CREATE is added.
The anonymous bpf iterator is seq_file based.
The seq_file private data are referenced by targets.
The bpf_iter infrastructure allocated additional space
at seq_file->private before the space used by targets
to store some meta data, e.g.,
prog: prog to run
session_id: an unique id for each opened seq_file
seq_num: how many times bpf programs are queried in this session
done_stop: an internal state to decide whether bpf program
should be called in seq_ops->stop() or not
The seq_num will start from 0 for valid objects.
The bpf program may see the same seq_num more than once if
- seq_file buffer overflow happens and the same object
is retried by bpf_seq_read(), or
- the bpf program explicitly requests a retry of the
same object
Since module is not supported for bpf_iter, all target
registeration happens at __init time, so there is no
need to change bpf_iter_unreg_target() as it is used
mostly in error path of the init function at which time
no bpf iterators have been created yet.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175905.2475770-1-yhs@fb.com
Diffstat (limited to 'tools/include')
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1e8dfff5d5d4..708763f702e1 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -116,6 +116,7 @@ enum bpf_cmd { BPF_LINK_GET_FD_BY_ID, BPF_LINK_GET_NEXT_ID, BPF_ENABLE_STATS, + BPF_ITER_CREATE, }; enum bpf_map_type { @@ -614,6 +615,11 @@ union bpf_attr { __u32 type; } enable_stats; + struct { /* struct used by BPF_ITER_CREATE command */ + __u32 link_fd; + __u32 flags; + } iter_create; + } __attribute__((aligned(8))); /* The description below is an attempt at providing documentation to eBPF |