Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open

From: Alexei Starovoitov
Date: Tue Apr 10 2018 - 00:56:11 EST


On 4/9/18 9:45 PM, Ravi Bangoria wrote:
Hi Song,

On 12/07/2017 04:15 AM, Song Liu wrote:
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.

Sorry for being late. One simple question..

Will it be good to support k/uprobe arguments with perf_event_open()?
Do you have any plans about that?

no plans for that. People that use text based interfaces should
probably be using text interfaces consistently.
imo mixing FD-based kprobe api with text is not worth the complexity.