Message ID | 20171211193903.2428317-1-yhs@fb.com |
---|---|
Headers | show |
Series | bpf/tracing: allow user space to query prog array on the same tp | expand |
On 12/11/2017 08:39 PM, Yonghong Song wrote: > Commit e87c6bc3852b ("bpf: permit multiple bpf attachments > for a single perf event") added support to attach multiple > bpf programs to a single perf event. Given a perf event > (kprobe, uprobe, or kernel tracepoint), the perf ioctl interface > is used to query bpf programs attached to the same trace event. > > There already exists a BPF_PROG_QUERY command for introspection > currently used by cgroup+bpf. We did have an implementation for > querying tracepoint+bpf through the same interface. However, it > looks cleaner to use ioctl() style of api here, since attaching > bpf prog to tracepoint/kuprobe is also done via ioctl. > > Patch #1 had the core implementation and patch #2 added > a test case in tools bpf selftests suite. > > Changelogs: > v3 -> v4: > - Fix a compilation error with newer gcc like 6.3.1 while > old gcc 4.8.5 is okay. I was using &uquery->ids to represent > the address to the ids array to make it explicit that the > address is passed, and this syntax is rightly rejected > by gcc 6.3.1. Series applied to bpf-next, thanks Yonghong.