Andrii Nakryiko <andriin@xxxxxx> writes:
> 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@xxxxxx>
> ---
> include/linux/bpf-cgroup.h | 2 -
> include/linux/bpf.h | 10 +-
> include/linux/bpf_types.h | 6 ++
> include/uapi/linux/bpf.h | 28 ++++++
> kernel/bpf/btf.c | 2 +
> kernel/bpf/cgroup.c | 45 ++++++++-
> kernel/bpf/syscall.c | 164 +++++++++++++++++++++++++++++----
> kernel/bpf/verifier.c | 2 +
> tools/include/uapi/linux/bpf.h | 31 +++++++
> 9 files changed, 266 insertions(+), 24 deletions(-)
>
> diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
> index d2d969669564..ab95824a1d99 100644
> --- a/include/linux/bpf-cgroup.h
> +++ b/include/linux/bpf-cgroup.h
> @@ -57,8 +57,6 @@ struct bpf_cgroup_link {
> enum bpf_attach_type type;
> };
>
> -extern const struct bpf_link_ops bpf_cgroup_link_lops;
> -
> struct bpf_prog_list {
> struct list_head node;
> struct bpf_prog *prog;
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 67ce74890911..8cf182d256d4 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1026,9 +1026,11 @@ extern const struct file_operations bpf_prog_fops;
> extern const struct bpf_verifier_ops _name ## _verifier_ops;
> #define BPF_MAP_TYPE(_id, _ops) \
> extern const struct bpf_map_ops _ops;
> +#define BPF_LINK_TYPE(_id, _name)
> #include <linux/bpf_types.h>
> #undef BPF_PROG_TYPE
> #undef BPF_MAP_TYPE
> +#undef BPF_LINK_TYPE
>
> extern const struct bpf_prog_ops bpf_offload_prog_ops;
> extern const struct bpf_verifier_ops tc_cls_act_analyzer_ops;
> @@ -1086,6 +1088,7 @@ int bpf_prog_new_fd(struct bpf_prog *prog);
> struct bpf_link {
> atomic64_t refcnt;
> u32 id;
> + enum bpf_link_type type;
> const struct bpf_link_ops *ops;
> struct bpf_prog *prog;
> struct work_struct work;
> @@ -1103,9 +1106,14 @@ struct bpf_link_ops {
> void (*dealloc)(struct bpf_link *link);
> int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog,
> struct bpf_prog *old_prog);
> + void (*show_fdinfo)(const struct bpf_link *link, struct seq_file *seq);
> + int (*fill_link_info)(const struct bpf_link *link,
> + struct bpf_link_info *info,
> + const struct bpf_link_info *uinfo,
> + u32 info_len);
> };
>
> -void bpf_link_init(struct bpf_link *link,
> +void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
> 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);
> diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
> index ba0c2d56f8a3..8345cdf553b8 100644
> --- a/include/linux/bpf_types.h
> +++ b/include/linux/bpf_types.h
> @@ -118,3 +118,9 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_STACK, stack_map_ops)
> #if defined(CONFIG_BPF_JIT)
> BPF_MAP_TYPE(BPF_MAP_TYPE_STRUCT_OPS, bpf_struct_ops_map_ops)
> #endif
> +
> +BPF_LINK_TYPE(BPF_LINK_TYPE_RAW_TRACEPOINT, raw_tracepoint)
> +BPF_LINK_TYPE(BPF_LINK_TYPE_TRACING, tracing)
> +#ifdef CONFIG_CGROUP_BPF
> +BPF_LINK_TYPE(BPF_LINK_TYPE_CGROUP, cgroup)
> +#endif
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 407c086bc9e4..d2f269082a33 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -222,6 +222,15 @@ enum bpf_attach_type {
>
> #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
>
> +enum bpf_link_type {
> + BPF_LINK_TYPE_UNSPEC = 0,
> + BPF_LINK_TYPE_RAW_TRACEPOINT = 1,
> + BPF_LINK_TYPE_TRACING = 2,
> + BPF_LINK_TYPE_CGROUP = 3,
> +
> + MAX_BPF_LINK_TYPE,
> +};
> +
> /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
> *
> * NONE(default): No further bpf programs allowed in the subtree.
> @@ -3601,6 +3610,25 @@ struct bpf_btf_info {
> __u32 id;
> } __attribute__((aligned(8)));
>
> +struct bpf_link_info {
> + __u32 type;
> + __u32 id;
> + __u32 prog_id;
> + union {
> + struct {
> + __aligned_u64 tp_name; /* in/out: tp_name buffer ptr */
> + __u32 tp_name_len; /* in/out: tp_name buffer len */
> + } raw_tracepoint;
> + struct {
> + __u32 attach_type;
> + } tracing;
Shouldn't this also include the attach target?
-Toke
