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| author | Andrii Nakryiko <andriin@fb.com> | 2020-04-28 17:16:06 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-04-28 17:27:08 -0700 |
| commit | a3b80e1078943dc12553166fb08e258463dec013 (patch) | |
| tree | e022212949f8028eacf0c5d3ad77218d7f1a7b1a /include/linux/bpf.h | |
| parent | f9d041271cf44ca02eed0cc82e1a6d8c814c53ed (diff) | |
| download | lwn-a3b80e1078943dc12553166fb08e258463dec013.tar.gz lwn-a3b80e1078943dc12553166fb08e258463dec013.zip | |
bpf: Allocate ID for bpf_link
Generate ID for each bpf_link using IDR, similarly to bpf_map and bpf_prog.
bpf_link creation, initialization, attachment, and exposing to user-space
through FD and ID is a complicated multi-step process, abstract it away
through bpf_link_primer and bpf_link_prime(), bpf_link_settle(), and
bpf_link_cleanup() internal API. They guarantee that until bpf_link is
properly attached, user-space won't be able to access partially-initialized
bpf_link either from FD or ID. All this allows to simplify bpf_link attachment
and error handling code.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-3-andriin@fb.com
Diffstat (limited to 'include/linux/bpf.h')
| -rw-r--r-- | include/linux/bpf.h | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 81c8620cb4c4..875d1f0af803 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1085,11 +1085,19 @@ int bpf_prog_new_fd(struct bpf_prog *prog); struct bpf_link { atomic64_t refcnt; + u32 id; const struct bpf_link_ops *ops; struct bpf_prog *prog; struct work_struct work; }; +struct bpf_link_primer { + struct bpf_link *link; + struct file *file; + int fd; + u32 id; +}; + struct bpf_link_ops { void (*release)(struct bpf_link *link); void (*dealloc)(struct bpf_link *link); @@ -1097,10 +1105,11 @@ struct bpf_link_ops { struct bpf_prog *old_prog); }; -void bpf_link_init(struct bpf_link *link, const struct bpf_link_ops *ops, - struct bpf_prog *prog); -void bpf_link_cleanup(struct bpf_link *link, struct file *link_file, - int link_fd); +void bpf_link_init(struct bpf_link *link, + const struct bpf_link_ops *ops, struct bpf_prog *prog); +int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer); +int bpf_link_settle(struct bpf_link_primer *primer); +void bpf_link_cleanup(struct bpf_link_primer *primer); void bpf_link_inc(struct bpf_link *link); void bpf_link_put(struct bpf_link *link); int bpf_link_new_fd(struct bpf_link *link); |