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author | Martin KaFai Lau <kafai@fb.com> | 2017-06-05 22:15:46 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-06-06 22:41:22 +0300 |
commit | dc4bb0e2356149aee4cdae061936f3bbdd45595c (patch) | |
tree | 519cc48437a65eade73ab7cb150e32076cbbc17e /include/linux/bpf.h | |
parent | 8ea4fae926afd81f4d7fd43444562afc8629f77c (diff) | |
download | linux-dc4bb0e2356149aee4cdae061936f3bbdd45595c.tar.xz |
bpf: Introduce bpf_prog ID
This patch generates an unique ID for each BPF_PROG_LOAD-ed prog.
It is worth to note that each BPF_PROG_LOAD-ed prog will have
a different ID even they have the same bpf instructions.
The ID is generated by the existing idr_alloc_cyclic().
The ID is ranged from [1, INT_MAX). It is allocated in cyclic manner,
so an ID will get reused every 2 billion BPF_PROG_LOAD.
The bpf_prog_alloc_id() is done after bpf_prog_select_runtime()
because the jit process may have allocated a new prog. Hence,
we need to ensure the value of pointer 'prog' will not be changed
any more before storing the prog to the prog_idr.
After bpf_prog_select_runtime(), the prog is read-only. Hence,
the id is stored in 'struct bpf_prog_aux'.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/bpf.h')
-rw-r--r-- | include/linux/bpf.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index fcc80ca11045..c5946d19f2ca 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -172,6 +172,7 @@ struct bpf_prog_aux { u32 used_map_cnt; u32 max_ctx_offset; u32 stack_depth; + u32 id; struct latch_tree_node ksym_tnode; struct list_head ksym_lnode; const struct bpf_verifier_ops *ops; |