Alexei suggested, 'link_type' can be more precise and differentiate for human in fdinfo. In fact BPF_LINK_TYPE_KPROBE_MULTI includes kretprobe_multi type, the same as BPF_LINK_TYPE_UPROBE_MULTI, so we can show it more concretely.
link_type: kprobe_multi link_id: 1 prog_tag: d2b307e915f0dd37 ... link_type: kretprobe_multi link_id: 2 prog_tag: ab9ea0545870781d ... link_type: uprobe_multi link_id: 9 prog_tag: e729f789e34a8eca ... link_type: uretprobe_multi link_id: 10 prog_tag: 7db356c03e61a4d4 As Andrii suggested attach_type can be recorded in bpf_link, there is still a 6 byte hole in bpf_link, we can fill the hole with attach_type soon. Co-authored-by: Jiri Olsa <[email protected]> Signed-off-by: Tao Chen <[email protected]> --- include/linux/bpf.h | 1 + kernel/bpf/syscall.c | 9 ++++++++- kernel/trace/bpf_trace.c | 10 ++++------ 3 files changed, 13 insertions(+), 7 deletions(-) Change list: v5 -> v6: - Move flags into bpf_link to get retprobe info directly.(Alexei, Jiri) v5: https://lore.kernel.org/bpf/[email protected] v4 -> v5: - Add patch1 to show precise link_type for {uprobe,kprobe}_multi.(Alexei) - patch2,3 just remove type field, which will be showed in link_type v4: https://lore.kernel.org/bpf/[email protected] v3 -> v4: - use %pS to print func info.(Alexei) v3: https://lore.kernel.org/bpf/[email protected] v2 -> v3: - show info in one line for multi events.(Jiri) v2: https://lore.kernel.org/bpf/[email protected] v1 -> v2: - replace 'func_cnt' with 'uprobe_cnt'.(Andrii) - print func name is more readable and security for kprobe_multi.(Alexei) v1: https://lore.kernel.org/bpf/[email protected] diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 5b25d278409..3d8fecc9b17 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1702,6 +1702,7 @@ struct bpf_link { * link's semantics is determined by target attach hook */ bool sleepable; + u32 flags :8; /* rcu is used before freeing, work can be used to schedule that * RCU-based freeing before that, so they never overlap */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 51ba1a7aa43..e6eea594f1c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3228,7 +3228,14 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { - seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); + if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) + seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? + "kretprobe_multi" : "kprobe_multi"); + else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) + seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ? + "uretprobe_multi" : "uprobe_multi"); + else + seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); } else { WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); seq_printf(m, "link_type:\t<%u>\n", type); diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 24b94870b50..85f07f662fe 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2469,7 +2469,6 @@ struct bpf_kprobe_multi_link { u32 cnt; u32 mods_cnt; struct module **mods; - u32 flags; }; struct bpf_kprobe_multi_run_ctx { @@ -2589,7 +2588,7 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); info->kprobe_multi.count = kmulti_link->cnt; - info->kprobe_multi.flags = kmulti_link->flags; + info->kprobe_multi.flags = kmulti_link->link.flags; info->kprobe_multi.missed = kmulti_link->fp.nmissed; if (!uaddrs) @@ -2979,7 +2978,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr link->addrs = addrs; link->cookies = cookies; link->cnt = cnt; - link->flags = flags; + link->link.flags = flags; if (cookies) { /* @@ -3048,7 +3047,6 @@ struct bpf_uprobe_multi_link { struct path path; struct bpf_link link; u32 cnt; - u32 flags; struct bpf_uprobe *uprobes; struct task_struct *task; }; @@ -3112,7 +3110,7 @@ static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); info->uprobe_multi.count = umulti_link->cnt; - info->uprobe_multi.flags = umulti_link->flags; + info->uprobe_multi.flags = umulti_link->link.flags; info->uprobe_multi.pid = umulti_link->task ? task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; @@ -3372,7 +3370,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr link->uprobes = uprobes; link->path = path; link->task = task; - link->flags = flags; + link->link.flags = flags; bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, &bpf_uprobe_multi_link_lops, prog); -- 2.48.1
