On Tue, May 15, 2018 at 04:45:16PM -0700, Yonghong Song wrote: > Currently, suppose a userspace application has loaded a bpf program > and attached it to a tracepoint/kprobe/uprobe, and a bpf > introspection tool, e.g., bpftool, wants to show which bpf program > is attached to which tracepoint/kprobe/uprobe. Such attachment > information will be really useful to understand the overall bpf > deployment in the system. > > There is a name field (16 bytes) for each program, which could > be used to encode the attachment point. There are some drawbacks > for this approaches. First, bpftool user (e.g., an admin) may not > really understand the association between the name and the > attachment point. Second, if one program is attached to multiple > places, encoding a proper name which can imply all these > attachments becomes difficult. > > This patch introduces a new bpf subcommand BPF_PERF_EVENT_QUERY. > Given a pid and fd, if the <pid, fd> is associated with a > tracepoint/kprobe/uprobea perf event, BPF_PERF_EVENT_QUERY will return > . prog_id > . tracepoint name, or > . k[ret]probe funcname + offset or kernel addr, or > . u[ret]probe filename + offset > to the userspace. > The user can use "bpftool prog" to find more information about > bpf program itself with prog_id. > > Signed-off-by: Yonghong Song <y...@fb.com> > --- > include/linux/trace_events.h | 15 ++++++ > include/uapi/linux/bpf.h | 25 ++++++++++ > kernel/bpf/syscall.c | 113 > +++++++++++++++++++++++++++++++++++++++++++ > kernel/trace/bpf_trace.c | 53 ++++++++++++++++++++ > kernel/trace/trace_kprobe.c | 29 +++++++++++ > kernel/trace/trace_uprobe.c | 22 +++++++++ > 6 files changed, 257 insertions(+)
Why is the command called *_PERF_EVENT_* ? Are there not a lot of !perf places to attach BPF proglets?
