Add support to specify cookies for tracing_multi link. Cookies are provided in array where each value is paired with provided BTF ID value with the same array index.
Such cookie can be retrieved by bpf program with bpf_get_attach_cookie helper call. Signed-off-by: Jiri Olsa <[email protected]> --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 1 + kernel/bpf/trampoline.c | 1 + kernel/trace/bpf_trace.c | 18 ++++++++++++++++++ tools/include/uapi/linux/bpf.h | 1 + 5 files changed, 22 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f22b9400a915..a919143a8b35 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1901,6 +1901,7 @@ struct bpf_tracing_multi_node { struct bpf_tracing_multi_link { struct bpf_link link; + u64 *cookies; int nodes_cnt; struct bpf_tracing_multi_node nodes[] __counted_by(nodes_cnt); }; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7f5c51f27a36..e28722ddeb5b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1866,6 +1866,7 @@ union bpf_attr { } cgroup; struct { __aligned_u64 ids; + __aligned_u64 cookies; __u32 cnt; } tracing_multi; }; diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index c42bf16b6807..1aa723dac209 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -1582,6 +1582,7 @@ int bpf_trampoline_multi_attach(struct bpf_prog *prog, u32 *ids, mnode = &link->nodes[i]; mnode->trampoline = tr; mnode->node.link = &link->link; + mnode->node.cookie = link->cookies ? link->cookies[i] : 0; } trampoline_lock_all(); diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a18aef19c3b5..b8932434e306 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3612,6 +3612,7 @@ static void bpf_tracing_multi_link_dealloc(struct bpf_link *link) struct bpf_tracing_multi_link *tr_link = container_of(link, struct bpf_tracing_multi_link, link); + kvfree(tr_link->cookies); kvfree(tr_link); } @@ -3625,6 +3626,8 @@ int bpf_tracing_multi_attach(struct bpf_prog *prog, const union bpf_attr *attr) struct bpf_tracing_multi_link *link = NULL; struct bpf_link_primer link_primer; u32 cnt, *ids = NULL; + u64 *cookies = NULL; + void __user *ucookies; u32 __user *uids; int err; @@ -3645,6 +3648,19 @@ int bpf_tracing_multi_attach(struct bpf_prog *prog, const union bpf_attr *attr) goto error; } + ucookies = u64_to_user_ptr(attr->link_create.tracing_multi.cookies); + if (ucookies) { + cookies = kvmalloc_array(cnt, sizeof(*cookies), GFP_KERNEL); + if (!cookies) { + err = -ENOMEM; + goto error; + } + if (copy_from_user(cookies, ucookies, cnt * sizeof(*cookies))) { + err = -EFAULT; + goto error; + } + } + link = kvzalloc(struct_size(link, nodes, cnt), GFP_KERNEL); if (!link) { err = -ENOMEM; @@ -3659,6 +3675,7 @@ int bpf_tracing_multi_attach(struct bpf_prog *prog, const union bpf_attr *attr) goto error; link->nodes_cnt = cnt; + link->cookies = cookies; err = bpf_trampoline_multi_attach(prog, ids, link); kvfree(ids); @@ -3669,6 +3686,7 @@ int bpf_tracing_multi_attach(struct bpf_prog *prog, const union bpf_attr *attr) return bpf_link_settle(&link_primer); error: + kvfree(cookies); kvfree(ids); kvfree(link); return err; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 7f5c51f27a36..e28722ddeb5b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1866,6 +1866,7 @@ union bpf_attr { } cgroup; struct { __aligned_u64 ids; + __aligned_u64 cookies; __u32 cnt; } tracing_multi; }; -- 2.53.0
