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 93a94669ca90..03d4ce0ef93e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1951,6 +1951,7 @@ struct bpf_tracing_multi_data { struct bpf_tracing_multi_link { struct bpf_link link; struct bpf_tracing_multi_data data; + 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 951a0122baaf..39407a77133b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1874,6 +1874,7 @@ 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 476b7db3a809..acccf52f6792 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -1613,6 +1613,7 @@ int bpf_trampoline_multi_attach(struct bpf_prog *prog, u32 *ids, mnode->trampoline = tr; mnode->node.link = &link->link; + mnode->node.cookie = link->cookies ? link->cookies[i] : 0; cond_resched(); } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 7cf22d69a1e1..6639751fab08 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3659,6 +3659,7 @@ 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); } @@ -3701,6 +3702,8 @@ 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 __user *ucookies; + u64 *cookies = NULL; u32 __user *uids; int err; @@ -3727,6 +3730,19 @@ int bpf_tracing_multi_attach(struct bpf_prog *prog, const union bpf_attr *attr) if (err) goto error; + ucookies = u64_to_user_ptr(attr->link_create.tracing_multi.cookies); + if (ucookies) { + cookies = kvmalloc_objs(*cookies, cnt); + if (!cookies) { + err = -ENOMEM; + goto error; + } + if (copy_from_user(cookies, ucookies, cnt * sizeof(*cookies))) { + err = -EFAULT; + goto error; + } + } + link = kvzalloc_flex(*link, nodes, cnt); if (!link) { err = -ENOMEM; @@ -3741,6 +3757,7 @@ 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); @@ -3751,6 +3768,7 @@ 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 951a0122baaf..39407a77133b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1874,6 +1874,7 @@ union bpf_attr { } cgroup; struct { __aligned_u64 ids; + __aligned_u64 cookies; __u32 cnt; } tracing_multi; }; -- 2.54.0
