diff options
| author | Andrii Nakryiko <andriin@fb.com> | 2020-04-28 17:16:08 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-04-28 17:27:08 -0700 |
| commit | f2e10bff16a0fdd41ba278c84da9813700e356af (patch) | |
| tree | 16f010477a98090542c424315f405b2f5e3b2d44 /kernel/bpf/cgroup.c | |
| parent | 2d602c8cf40d65d4a7ac34fe18648d8778e6e594 (diff) | |
bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link
Add ability to fetch bpf_link details through BPF_OBJ_GET_INFO_BY_FD command.
Also enhance show_fdinfo to potentially include bpf_link type-specific
information (similarly to obj_info).
Also introduce enum bpf_link_type stored in bpf_link itself and expose it in
UAPI. bpf_link_tracing also now will store and return bpf_attach_type.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-5-andriin@fb.com
Diffstat (limited to 'kernel/bpf/cgroup.c')
| -rw-r--r-- | kernel/bpf/cgroup.c | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 1bdf37fca879..5c0e964105ac 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -833,10 +833,48 @@ static void bpf_cgroup_link_dealloc(struct bpf_link *link) kfree(cg_link); } -const struct bpf_link_ops bpf_cgroup_link_lops = { +static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + struct bpf_cgroup_link *cg_link = + container_of(link, struct bpf_cgroup_link, link); + u64 cg_id = 0; + + mutex_lock(&cgroup_mutex); + if (cg_link->cgroup) + cg_id = cgroup_id(cg_link->cgroup); + mutex_unlock(&cgroup_mutex); + + seq_printf(seq, + "cgroup_id:\t%llu\n" + "attach_type:\t%d\n", + cg_id, + cg_link->type); +} + +static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + struct bpf_cgroup_link *cg_link = + container_of(link, struct bpf_cgroup_link, link); + u64 cg_id = 0; + + mutex_lock(&cgroup_mutex); + if (cg_link->cgroup) + cg_id = cgroup_id(cg_link->cgroup); + mutex_unlock(&cgroup_mutex); + + info->cgroup.cgroup_id = cg_id; + info->cgroup.attach_type = cg_link->type; + return 0; +} + +static const struct bpf_link_ops bpf_cgroup_link_lops = { .release = bpf_cgroup_link_release, .dealloc = bpf_cgroup_link_dealloc, .update_prog = cgroup_bpf_replace, + .show_fdinfo = bpf_cgroup_link_show_fdinfo, + .fill_link_info = bpf_cgroup_link_fill_link_info, }; int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) @@ -858,7 +896,8 @@ int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) err = -ENOMEM; goto out_put_cgroup; } - bpf_link_init(&link->link, &bpf_cgroup_link_lops, prog); + bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops, + prog); link->cgroup = cgrp; link->type = attr->link_create.attach_type; |