On Dec 8, 2017, at 11:57 AM, Daniel Borkmann [off-list ref] wrote:
On 12/06/2017 11:45 PM, Song Liu wrote:
quoted
Changes PATCH v4 to PATCH v5:
Remove PERF_PROBE_CONFIG_IS_RETPROBE from uapi, use PMU_FORMAT_ATTR
instead.
Changes PATCH v3 to PATCH v4:
Remove uapi define MAX_PROBE_FUNC_NAME_LEN, use KSYM_NAME_LEN instead.
Add flag PERF_PROBE_CONFIG_IS_RETPROBE for config field of [k,u]probe.
Optimize ifdef's of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS.
Optimize checks in perf_event_is_tracing().
Optimize perf_tp_register().
Changes PATCH v2 to PATCH v3:
Remove fixed type PERF_TYPE_KPROBE and PERF_TYPE_UPROBE, use dynamic
type instead.
Update userspace (samples/bpf, bcc) to look up type from sysfs.
Change License info in test_many_kprobe_user.c as Philippe Ombredanne
suggested.
Changes PATCH v1 to PATCH v2:
Split PERF_TYPE_PROBE into PERF_TYPE_KPROBE and PERF_TYPE_UPROBE.
Split perf_probe into perf_kprobe and perf_uprobe.
Remove struct probe_desc, use config1 and config2 instead.
Changes RFC v2 to PATCH v1:
Check type PERF_TYPE_PROBE in perf_event_set_filter().
Rebase on to tip perf/core.
Changes RFC v1 to RFC v2:
Fix build issue reported by kbuild test bot by adding ifdef of
CONFIG_KPROBE_EVENTS, and CONFIG_UPROBE_EVENTS.
RFC v1 cover letter:
This is to follow up the discussion over "new kprobe api" at Linux
Plumbers 2017:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.linuxplumbersconf.org_2017_ocw_proposals_4808&d=DwICaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=dR8692q0_uaizy0jkrBJQM5k2hfm4CiFxYT8KaysFrg&m=iAtBi3jXPYfFgvhHTsv8oWyUKiyEwnGZ34-4jniREz4&s=87sxRxoRkJJenQjCtFLJFXkMLvd_rHkY8ZGON9em1Jc&e=
With current kernel, user space tools can only create/destroy [k,u]probes
with a text-based API (kprobe_events and uprobe_events in tracefs). This
approach relies on user space to clean up the [k,u]probe after using them.
However, this is not easy for user space to clean up properly.
To solve this problem, we introduce a file descriptor based API.
Specifically, we extended perf_event_open to create [k,u]probe, and attach
this [k,u]probe to the file descriptor created by perf_event_open. These
[k,u]probe are associated with this file descriptor, so they are not
available in tracefs.
We reuse large portion of existing trace_kprobe and trace_uprobe code.
Currently, the file descriptor API does not support arguments as the
text-based API does. This should not be a problem, as user of the file
decriptor based API read data through other methods (bpf, etc.).
I also include a patch to to bcc, and a patch to man-page perf_even_open.
Please see the list below. A fork of bcc with this patch is also available
on github:
https://github.com/liu-song-6/bcc/tree/perf_event_open
Peter / Stephen, I presume this will be routed through one of you, if
not please yell.
Thanks,
Daniel
Dear Peter,
Do you have further feedbacks/comments on these patches? If not, could you
please confirm they are ready for merge?
Thanks and Best Regards,
Song