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Wed, 27 Aug 2025 05:38:24 -0700 (PDT) Received: from 7940hx ([43.129.244.20]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-24692f981c9sm104588115ad.116.2025.08.27.05.38.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Aug 2025 05:38:23 -0700 (PDT) From: Menglong Dong X-Google-Original-From: Menglong Dong To: jolsa@kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, mattbobrowski@google.com, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH bpf-next] bpf: remove unnecessary rcu_read_lock in kprobe_multi_link_prog_run Date: Wed, 27 Aug 2025 20:38:14 +0800 Message-ID: <20250827123814.60217-1-dongml2@chinatelecom.cn> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Preemption is disabled in ftrace graph, which indicate rcu_read_lock. So the rcu_read_lock is not needed in fprobe_entry(), and it is not needed in kprobe_multi_link_prog_run() neither. Signed-off-by: Menglong Dong --- kernel/trace/bpf_trace.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 606007c387c5..0e79fa84a634 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2741,12 +2741,10 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_= link *link, goto out; } =20 - rcu_read_lock(); regs =3D ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); old_run_ctx =3D bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); err =3D bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); - rcu_read_unlock(); =20 out: __this_cpu_dec(bpf_prog_active); --=20 2.51.0