[RFC PATCH 0/6] fprobe: Introduce fprobe function entry/exit probe

Masami Hiramatsu
2022-01-11T15:00:38Z

Hi Jiri,

Here is a short series of patches, which shows what I replied
to your series.

This introduces the fprobe, the function entry/exit probe with
multiple probe point support. This also introduces the rethook
for hooking function return, which I cloned from kretprobe.

I also rewrite your [08/13] bpf patch to use this fprobe instead
of kprobes. I didn't tested that one, but the sample module seems
to work. Please test bpf part with your libbpf updates.

BTW, while implementing the fprobe, I introduced the per-probe
point private data, but I'm not sure why you need it. It seems
that data is not used from bpf...

If this is good for you, I would like to proceed this with
the rethook and rewrite the kretprobe to use the rethook to
hook the functions. That should be much cleaner (and easy to
prepare for the fgraph tracer integration)

Thank you,

---

Jiri Olsa (1):
bpf: Add kprobe link for attaching raw kprobes

Masami Hiramatsu (5):
fprobe: Add ftrace based probe APIs
rethook: Add a generic return hook
rethook: x86: Add rethook x86 implementation
fprobe: Add exit_handler support
fprobe: Add sample program for fprobe

arch/x86/Kconfig | 1
arch/x86/kernel/Makefile | 1
arch/x86/kernel/rethook.c | 115 ++++++++++++++++++++
include/linux/bpf_types.h | 1
include/linux/fprobes.h | 75 +++++++++++++
include/linux/rethook.h | 74 +++++++++++++
include/linux/sched.h | 3 +
include/uapi/linux/bpf.h | 12 ++
kernel/bpf/syscall.c | 199 +++++++++++++++++++++++++++++++++-
kernel/exit.c | 2
kernel/fork.c | 3 +
kernel/trace/Kconfig | 22 ++++
kernel/trace/Makefile | 2
kernel/trace/fprobes.c | 187 ++++++++++++++++++++++++++++++++
kernel/trace/rethook.c | 226 +++++++++++++++++++++++++++++++++++++++
samples/Kconfig | 6 +
samples/Makefile | 1
samples/fprobe/Makefile | 3 +
samples/fprobe/fprobe_example.c | 103 ++++++++++++++++++
tools/include/uapi/linux/bpf.h | 12 ++
20 files changed, 1043 insertions(+), 5 deletions(-)
create mode 100644 arch/x86/kernel/rethook.c
create mode 100644 include/linux/fprobes.h
create mode 100644 include/linux/rethook.h
create mode 100644 kernel/trace/fprobes.c
create mode 100644 kernel/trace/rethook.c
create mode 100644 samples/fprobe/Makefile
create mode 100644 samples/fprobe/fprobe_example.c

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>