From: Steven Rostedt <rostedt@goodmis.org>
To: 梦龙董 <dongmenglong.8@bytedance.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Jiri Olsa <jolsa@kernel.org>, Andrii Nakryiko <andrii@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eddy Z <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Sven Schnelle <svens@linux.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
David Ahern <dsahern@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
X86 ML <x86@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Quentin Monnet <quentin@isovalent.com>, bpf <bpf@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-riscv <linux-riscv@lists.infradead.org>,
linux-s390 <linux-s390@vger.kernel.org>,
Network Development <netdev@vger.kernel.org>,
linux-trace-kernel@vger.kernel.org,
"open list:KERNEL SELFTEST FRAMEWORK"
<linux-kselftest@vger.kernel.org>,
linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [External] Re: [PATCH bpf-next v2 1/9] bpf: tracing: add support to record and check the accessed args
Date: Mon, 1 Apr 2024 11:59:28 -0400 [thread overview]
Message-ID: <20240401115928.3d012be2@gandalf.local.home> (raw)
In-Reply-To: <CALz3k9j_RGqSMdN+GvbHEjRqMWYe4R9VNZRANG7jbfL_jVpoVg@mail.gmail.com>
On Mon, 1 Apr 2024 10:28:17 +0800
梦龙董 <dongmenglong.8@bytedance.com> wrote:
> On Sun, Mar 31, 2024 at 3:34 AM Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > On Sat, 30 Mar 2024 11:18:29 +0800
> > 梦龙董 <dongmenglong.8@bytedance.com> wrote:
> >
> > > > If you really want to have thousands of functions, why not just register it
> > > > with ftrace itself. It will give you the arguments via the ftrace_regs
> > > > structure. Can't you just register a program as the callback?
> > > >
> > >
> > > Ennn...I don't understand. The main purpose for
> > > me to use TRACING is:
> > >
> > > 1. we can directly access the memory, which is more
> > > efficient.
> >
> > I'm not sure what you mean by the above. Access what memory?
> >
>
> We need to use the helper of bpf_probe_read_kernel
> when we read "skb->sk" in kprobe, and the "skb" is the
> 1st arg in ip_rcv(). And we can directly read "skb->sk"
> in tracing, which is more efficient. Isn't it?
If you add a ftrace_ops function handler that calls a BPF program, I don't
see why you can't just give it the parameters it needs instead of using bpf
helpers. It's no different than using a trampoline to do the same thing.
-- Steve
next prev parent reply other threads:[~2024-04-01 15:57 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-11 9:35 [PATCH bpf-next v2 0/9] bpf: make tracing program support multi-link Menglong Dong
2024-03-11 9:35 ` [PATCH bpf-next v2 1/9] bpf: tracing: add support to record and check the accessed args Menglong Dong
2024-03-12 1:46 ` Alexei Starovoitov
2024-03-12 2:01 ` [External] " 梦龙董
2024-03-12 2:09 ` Alexei Starovoitov
2024-03-12 2:42 ` 梦龙董
2024-03-12 2:49 ` 梦龙董
2024-03-12 16:42 ` Alexei Starovoitov
2024-03-13 1:53 ` 梦龙董
2024-03-14 0:25 ` Alexei Starovoitov
2024-03-14 6:27 ` Jiri Olsa
2024-03-15 8:17 ` 梦龙董
2024-03-15 8:00 ` 梦龙董
2024-03-28 14:43 ` 梦龙董
2024-03-28 15:13 ` Steven Rostedt
2024-03-28 23:17 ` Alexei Starovoitov
2024-03-30 3:36 ` 梦龙董
2024-03-29 23:28 ` Andrii Nakryiko
2024-03-29 23:28 ` Andrii Nakryiko
2024-03-29 23:28 ` Andrii Nakryiko
2024-03-30 4:16 ` 梦龙董
2024-03-30 12:27 ` Steven Rostedt
2024-03-30 17:52 ` Jiri Olsa
2024-03-31 2:34 ` Andrii Nakryiko
2024-03-31 2:34 ` Andrii Nakryiko
2024-03-30 3:18 ` 梦龙董
2024-03-30 19:37 ` Steven Rostedt
2024-04-01 2:28 ` 梦龙董
2024-04-01 15:59 ` Steven Rostedt [this message]
2024-03-11 9:35 ` [PATCH bpf-next v2 2/9] bpf: refactor the modules_array to ptr_array Menglong Dong
2024-03-12 1:48 ` Alexei Starovoitov
2024-03-12 1:53 ` [External] " 梦龙董
2024-03-11 9:35 ` [PATCH bpf-next v2 3/9] bpf: trampoline: introduce struct bpf_tramp_link_conn Menglong Dong
2024-03-11 9:35 ` [PATCH bpf-next v2 4/9] bpf: trampoline: introduce bpf_tramp_multi_link Menglong Dong
2024-03-11 9:35 ` [PATCH bpf-next v2 5/9] bpf: verifier: add btf to the function args of bpf_check_attach_target Menglong Dong
2024-03-12 1:51 ` Alexei Starovoitov
2024-03-12 3:13 ` [External] " 梦龙董
2024-03-11 9:35 ` [PATCH bpf-next v2 6/9] bpf: tracing: add multi-link support Menglong Dong
2024-03-11 18:59 ` kernel test robot
2024-03-11 21:36 ` kernel test robot
2024-03-11 9:35 ` [PATCH bpf-next v2 7/9] libbpf: don't free btf if program of multi-link tracing existing Menglong Dong
2024-03-12 1:55 ` Alexei Starovoitov
2024-03-12 2:05 ` [External] " 梦龙董
2024-03-12 2:13 ` Alexei Starovoitov
2024-03-12 2:56 ` 梦龙董
2024-03-11 9:35 ` [PATCH bpf-next v2 8/9] libbpf: add support for the multi-link of tracing Menglong Dong
2024-03-11 15:29 ` Quentin Monnet
2024-03-12 1:43 ` [External] " 梦龙董
2024-03-12 1:56 ` Alexei Starovoitov
2024-03-12 2:44 ` [External] " 梦龙董
2024-03-12 16:11 ` Alexei Starovoitov
2024-03-13 1:14 ` 梦龙董
2024-03-11 9:35 ` [PATCH bpf-next v2 9/9] selftests/bpf: add testcases for " Menglong Dong
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