On Thu, Jun 8, 2023 at 3:35 AM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
> By introducing support for ->fill_link_info to the perf_event link, users
> gain the ability to inspect it using `bpftool link show`. While the current
> approach involves accessing this information via `bpftool perf show`,
> consolidating link information for all link types in one place offers
> greater convenience. Additionally, this patch extends support to the
> generic perf event, which is not currently accommodated by
> `bpftool perf show`. While only the perf type and config are exposed to
> userspace, other attributes such as sample_period and sample_freq are
> ignored. It's important to note that if kptr_restrict is set to 2, the
> probed address will not be exposed, maintaining security measures.
>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> ---
> include/uapi/linux/bpf.h | 22 ++++++++++
> kernel/bpf/syscall.c | 98 ++++++++++++++++++++++++++++++++++++++++++
> tools/include/uapi/linux/bpf.h | 22 ++++++++++
> 3 files changed, 142 insertions(+)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index d99cc16..c3b821d 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -6443,6 +6443,28 @@ struct bpf_link_info {
> __u32 count;
> __u8 retprobe;
> } kprobe_multi;
> + union {
> + struct {
> + /* The name is:
> + * a) uprobe: file name
> + * b) kprobe: kernel function
> + */
> + __aligned_u64 name; /* in/out: name buffer ptr */
> + __u32 name_len;
> + __u32 offset; /* offset from the name */
> + __u64 addr;
> + __u8 retprobe;
> + } probe; /* uprobe, kprobe */
> + struct {
> + /* in/out: tracepoint name buffer ptr */
> + __aligned_u64 tp_name;
> + __u32 name_len;
> + } tp; /* tracepoint */
> + struct {
> + __u64 config;
> + __u32 type;
> + } event; /* generic perf event */
how should the user know which of those structs are relevant? we need
some enum to specify what kind of perf_event link it is?
> + } perf_event;
> };
> } __attribute__((aligned(8)));
>
[...]
