From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 08/13] bpf: Add kprobe link for attaching raw kprobes
Date: Thu, 6 Jan 2022 13:53:05 -0800 [thread overview]
Message-ID: <CAEf4BzZbt1eVKtUaO4b1eEBpTZ3_47t6a_5YtnYGLA9-ZCJCDg@mail.gmail.com> (raw)
In-Reply-To: <CAADnVQJdgt41wprEmCdEgpQMii-AHm9ZesZX6gypNuTefntmEA@mail.gmail.com>
On Thu, Jan 6, 2022 at 8:32 AM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Thu, Jan 6, 2022 at 12:41 AM Jiri Olsa <jolsa@redhat.com> wrote:
> >
> > On Wed, Jan 05, 2022 at 08:30:56PM -0800, Andrii Nakryiko wrote:
> > > On Tue, Jan 4, 2022 at 12:10 AM Jiri Olsa <jolsa@redhat.com> wrote:
> > > >
> > > > Adding new link type BPF_LINK_TYPE_KPROBE to attach kprobes
> > > > directly through register_kprobe/kretprobe API.
> > > >
> > > > Adding new attach type BPF_TRACE_RAW_KPROBE that enables
> > > > such link for kprobe program.
> > > >
> > > > The new link allows to create multiple kprobes link by using
> > > > new link_create interface:
> > > >
> > > > struct {
> > > > __aligned_u64 addrs;
> > > > __u32 cnt;
> > > > __u64 bpf_cookie;
> > >
> > > I'm afraid bpf_cookie has to be different for each addr, otherwise
> > > it's severely limiting. So it would be an array of cookies alongside
> > > an array of addresses
> >
> > ok
> >
> > >
> > > > } kprobe;
> > > >
> > > > Plus new flag BPF_F_KPROBE_RETURN for link_create.flags to
> > > > create return probe.
> > > >
> > > > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > > > ---
> > > > include/linux/bpf_types.h | 1 +
> > > > include/uapi/linux/bpf.h | 12 +++
> > > > kernel/bpf/syscall.c | 191 ++++++++++++++++++++++++++++++++-
> > > > tools/include/uapi/linux/bpf.h | 12 +++
> > > > 4 files changed, 211 insertions(+), 5 deletions(-)
> > > >
> > >
> > > [...]
> > >
> > > > @@ -1111,6 +1113,11 @@ enum bpf_link_type {
> > > > */
> > > > #define BPF_F_SLEEPABLE (1U << 4)
> > > >
> > > > +/* link_create flags used in LINK_CREATE command for BPF_TRACE_RAW_KPROBE
> > > > + * attach type.
> > > > + */
> > > > +#define BPF_F_KPROBE_RETURN (1U << 0)
> > > > +
> > >
> > > we have plenty of flexibility to have per-link type fields, so why not
> > > add `bool is_retprobe` next to addrs and cnt?
> >
> > well I thought if I do that, people would suggest to use the empty
> > flags field instead ;-)
> >
> > we can move it there as you suggest, but I wonder it's good idea to
> > use bool in uapi headers, because the bool size definition is vague
>
> Good point. No 'bool' please.
> grep bool include/uapi/linux/
> Only gives openvswitch.h and it's guarded by ifdef KERNEL
> So not a single uapi header has bool in it.
Yeah, I don't insist on bool specifically.
But I was trying to avoid link_create.flags to become map_flags where
we have various flags, each taking a separate bit, but most flags
don't apply to most map types. Ideally link_create.flags would have
few flags that apply to all or most link types (i.e., something
orthogonal to a specific link type), and for this case we could have
kprobe-specific flags (link_create.kprobe.flags) to adjust kprobe link
creation behavior.
But I don't know, maybe I'm overthinking this.
next prev parent reply other threads:[~2022-01-06 21:53 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-04 8:09 [RFC 00/13] kprobe/bpf: Add support to attach multiple kprobes Jiri Olsa
2022-01-04 8:09 ` [PATCH 01/13] ftrace: Add ftrace_set_filter_ips function Jiri Olsa
2022-01-04 8:09 ` [PATCH 02/13] kprobe: Keep traced function address Jiri Olsa
2022-01-05 14:32 ` Masami Hiramatsu
2022-01-06 8:30 ` Jiri Olsa
2022-01-06 4:30 ` Andrii Nakryiko
2022-01-06 8:31 ` Jiri Olsa
2022-01-04 8:09 ` [PATCH 03/13] kprobe: Add support to register multiple ftrace kprobes Jiri Olsa
2022-01-05 15:00 ` Masami Hiramatsu
2022-01-04 8:09 ` [PATCH 04/13] kprobe: Add support to register multiple ftrace kretprobes Jiri Olsa
2022-01-04 8:09 ` [PATCH 05/13] kprobe: Allow to get traced function address for multi ftrace kprobes Jiri Olsa
2022-01-06 4:30 ` Andrii Nakryiko
2022-01-04 8:09 ` [PATCH 06/13] samples/kprobes: Add support for multi kprobe interface Jiri Olsa
2022-01-04 8:09 ` [PATCH 07/13] samples/kprobes: Add support for multi kretprobe interface Jiri Olsa
2022-01-04 8:09 ` [PATCH 08/13] bpf: Add kprobe link for attaching raw kprobes Jiri Olsa
2022-01-06 4:30 ` Andrii Nakryiko
2022-01-06 8:41 ` Jiri Olsa
2022-01-06 16:32 ` Alexei Starovoitov
2022-01-06 21:53 ` Andrii Nakryiko [this message]
2022-01-04 8:09 ` [PATCH 09/13] libbpf: Add libbpf__kallsyms_parse function Jiri Olsa
2022-01-04 8:09 ` [PATCH 10/13] libbpf: Add bpf_link_create support for multi kprobes Jiri Olsa
2022-01-04 8:09 ` [PATCH 11/13] libbpf: Add bpf_program__attach_kprobe_opts " Jiri Olsa
2022-01-04 8:09 ` [PATCH 12/13] selftest/bpf: Add raw kprobe attach test Jiri Olsa
2022-01-04 8:09 ` [PATCH 13/13] selftest/bpf: Add bpf_cookie test for raw_k[ret]probe Jiri Olsa
2022-01-04 18:53 ` [RFC 00/13] kprobe/bpf: Add support to attach multiple kprobes Alexei Starovoitov
2022-01-05 9:15 ` Jiri Olsa
2022-01-05 15:24 ` Masami Hiramatsu
2022-01-06 8:29 ` Jiri Olsa
2022-01-06 13:59 ` Masami Hiramatsu
2022-01-06 14:57 ` Jiri Olsa
2022-01-07 5:42 ` Masami Hiramatsu
2022-01-06 15:02 ` Steven Rostedt
2022-01-06 17:40 ` Alexei Starovoitov
2022-01-06 23:52 ` Masami Hiramatsu
2022-01-07 0:20 ` Alexei Starovoitov
2022-01-07 12:55 ` Masami Hiramatsu
2022-01-11 15:00 ` [RFC PATCH 0/6] fprobe: Introduce fprobe function entry/exit probe Masami Hiramatsu
2022-01-11 15:00 ` [RFC PATCH 1/6] fprobe: Add ftrace based probe APIs Masami Hiramatsu
2022-01-11 15:00 ` [RFC PATCH 2/6] rethook: Add a generic return hook Masami Hiramatsu
2022-01-11 15:00 ` [RFC PATCH 3/6] rethook: x86: Add rethook x86 implementation Masami Hiramatsu
2022-01-11 15:01 ` [RFC PATCH 4/6] fprobe: Add exit_handler support Masami Hiramatsu
2022-01-11 15:01 ` [RFC PATCH 5/6] fprobe: Add sample program for fprobe Masami Hiramatsu
2022-01-11 15:01 ` [RFC PATCH 6/6] bpf: Add kprobe link for attaching raw kprobes Masami Hiramatsu
2022-01-11 22:39 ` [RFC PATCH 0/6] fprobe: Introduce fprobe function entry/exit probe Alexei Starovoitov
2022-01-12 7:33 ` Masami Hiramatsu
2022-01-12 11:08 ` Masami Hiramatsu
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