From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: linux-kernel@vger.kernel.org
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>,
Adrian Ratiu <adrian.ratiu@collabora.com>,
Alexei Starovoitov <ast@kernel.org>,
bpf@vger.kernel.org, Brendan Gregg <brendan.d.gregg@gmail.com>,
connoro@google.com, Daniel Borkmann <daniel@iogearbox.net>,
duyuchao <yuchao.du@unisoc.com>, Ingo Molnar <mingo@redhat.com>,
jeffv@google.com, Karim Yaghmour <karim.yaghmour@opersys.com>,
kernel-team@android.com, linux-kselftest@vger.kernel.org,
Manali Shukla <manalishukla14@gmail.com>,
Manjo Raja Rao <linux@manojrajarao.com>,
Martin KaFai Lau <kafai@fb.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Matt Mullins <mmullins@fb.com>,
Michal Gregorczyk <michalgr@fb.com>,
Michal Gregorczyk <michalgr@live.com>,
Mohammad Husain <russoue@gmail.com>,
namhyung@google.com, namhyung@kernel.org, netdev@vger.kernel.org,
paul.chaignon@gmail.com, primiano@google.com,
Qais Yousef <qais.yousef@arm.com>, Shuah Khan <shuah@kernel.org>,
Song Liu <songliubraving@fb.com>,
Srinivas Ramana <sramana@codeaurora.org>,
Steven Rostedt <rostedt@goodmis.org>,
Tamir Carmeli <carmeli.tamir@gmail.com>,
Yonghong Song <yhs@fb.com>
Subject: [PATCH RFC 0/4] Add support to directly attach BPF program to ftrace
Date: Wed, 10 Jul 2019 10:15:44 -0400 [thread overview]
Message-ID: <20190710141548.132193-1-joel@joelfernandes.org> (raw)
Hi,
These patches make it possible to attach BPF programs directly to tracepoints
using ftrace (/sys/kernel/debug/tracing) without needing the process doing the
attach to be alive. This has the following benefits:
1. Simplified Security: In Android, we have finer-grained security controls to
specific ftrace trace events using SELinux labels. We control precisely who is
allowed to enable an ftrace event already. By adding a node to ftrace for
attaching BPF programs, we can use the same mechanism to further control who is
allowed to attach to a trace event.
2. Process lifetime: In Android we are adding usecases where a tracing program
needs to be attached all the time to a tracepoint, for the full life time of
the system. Such as to gather statistics where there no need for a detach for
the full system lifetime. With perf or bpf(2)'s BPF_RAW_TRACEPOINT_OPEN, this
means keeping a process alive all the time. However, in Android our BPF loader
currently (for hardeneded security) involves just starting a process at boot
time, doing the BPF program loading, and then pinning them to /sys/fs/bpf. We
don't keep this process alive all the time. It is more suitable to do a
one-shot attach of the program using ftrace and not need to have a process
alive all the time anymore for this. Such process also needs elevated
privileges since tracepoint program loading currently requires CAP_SYS_ADMIN
anyway so by design Android's bpfloader runs once at init and exits.
This series add a new bpf file to /sys/kernel/debug/tracing/events/X/Y/bpf
The following commands can be written into it:
attach:<fd> Attaches BPF prog fd to tracepoint
detach:<fd> Detaches BPF prog fd to tracepoint
Reading the bpf file will show all the attached programs to the tracepoint.
Joel Fernandes (Google) (4):
Move bpf_raw_tracepoint functionality into bpf_trace.c
trace/bpf: Add support for attach/detach of ftrace events to BPF
lib/bpf: Add support for ftrace event attach and detach
selftests/bpf: Add test for ftrace-based BPF attach/detach
include/linux/bpf_trace.h | 16 ++
include/linux/trace_events.h | 1 +
kernel/bpf/syscall.c | 69 +-----
kernel/trace/bpf_trace.c | 225 ++++++++++++++++++
kernel/trace/trace.h | 1 +
kernel/trace/trace_events.c | 8 +
tools/lib/bpf/bpf.c | 53 +++++
tools/lib/bpf/bpf.h | 4 +
tools/lib/bpf/libbpf.map | 2 +
.../raw_tp_writable_test_ftrace_run.c | 89 +++++++
10 files changed, 410 insertions(+), 58 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/raw_tp_writable_test_ftrace_run.c
--
2.22.0.410.gd8fdbe21b5-goog
next reply other threads:[~2019-07-10 14:15 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-10 14:15 Joel Fernandes (Google) [this message]
2019-07-10 14:15 ` [PATCH RFC 1/4] Move bpf_raw_tracepoint functionality into bpf_trace.c Joel Fernandes (Google)
2019-07-10 14:15 ` [PATCH RFC 2/4] trace/bpf: Add support for attach/detach of ftrace events to BPF Joel Fernandes (Google)
2019-07-10 14:15 ` [PATCH RFC 3/4] lib/bpf: Add support for ftrace event attach and detach Joel Fernandes (Google)
2019-07-10 14:15 ` [PATCH RFC 4/4] selftests/bpf: Add test for ftrace-based BPF attach/detach Joel Fernandes (Google)
2019-07-16 20:54 ` [PATCH RFC 0/4] Add support to directly attach BPF program to ftrace Alexei Starovoitov
2019-07-16 21:30 ` Joel Fernandes
2019-07-16 22:26 ` Alexei Starovoitov
2019-07-16 22:41 ` Joel Fernandes
2019-07-16 23:55 ` Joel Fernandes
2019-07-17 1:24 ` Alexei Starovoitov
2019-07-17 13:01 ` Joel Fernandes
2019-07-17 21:40 ` Alexei Starovoitov
2019-07-18 2:51 ` Joel Fernandes
2019-07-23 22:11 ` Alexei Starovoitov
2019-07-24 13:57 ` Joel Fernandes
2019-07-26 18:39 ` Alexei Starovoitov
2019-07-26 19:18 ` Joel Fernandes
2019-07-26 19:49 ` Joel Fernandes
2019-07-16 22:43 ` Steven Rostedt
2019-07-16 22:31 ` Steven Rostedt
2019-07-16 22:46 ` Joel Fernandes
2019-07-17 1:30 ` Alexei Starovoitov
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