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 Signed-off-by: Tao Chen <[email protected]> --- include/linux/trace_events.h | 10 ++++++++++ kernel/bpf/syscall.c | 9 ++++++++- kernel/trace/bpf_trace.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+), 1 deletion(-) Change list: 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/trace_events.h b/include/linux/trace_events.h index fa9cf4292df..951c91babbc 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -780,6 +780,8 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, unsigned long *missed); int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); +void bpf_kprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, int len); +void bpf_uprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, int len); #else static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) { @@ -832,6 +834,14 @@ bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { return -EOPNOTSUPP; } +static inline void +bpf_kprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, int len) +{ +} +static inline void +bpf_uprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, int len) +{ +} #endif enum { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 51ba1a7aa43..43b821b37bc 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3226,9 +3226,16 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) const struct bpf_prog *prog = link->prog; enum bpf_link_type type = link->type; char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; + char link_type[64] = {}; 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) + bpf_kprobe_multi_link_type_show(link, link_type, sizeof(link_type)); + else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) + bpf_uprobe_multi_link_type_show(link, link_type, sizeof(link_type)); + else + strscpy(link_type, bpf_link_type_strs[type], sizeof(link_type)); + seq_printf(m, "link_type:\t%s\n", link_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..8ecb1a9f85d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3016,7 +3016,21 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr kvfree(cookies); return err; } + +void bpf_kprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, + int len) +{ + struct bpf_kprobe_multi_link *kmulti_link; + + kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); + strscpy(link_type, kmulti_link->flags == BPF_F_KPROBE_MULTI_RETURN ? + "kretprobe_multi" : "kprobe_multi", len); +} #else /* !CONFIG_FPROBE */ +void bpf_kprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, + int len) +{ +} int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { return -EOPNOTSUPP; @@ -3407,7 +3421,21 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr path_put(&path); return err; } + +void bpf_uprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, + int len) +{ + struct bpf_uprobe_multi_link *umulti_link; + + umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); + strscpy(link_type, umulti_link->flags == BPF_F_UPROBE_MULTI_RETURN ? + "uretprobe_multi" : "uprobe_multi", len); +} #else /* !CONFIG_UPROBES */ +void bpf_uprobe_multi_link_type_show(const struct bpf_link *link, char *link_type, + int len) +{ +} int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { return -EOPNOTSUPP; -- 2.48.1
