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Fri, 26 Sep 2025 23:12:19 -0700 (PDT) From: Menglong Dong X-Google-Original-From: Menglong Dong To: ast@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, jiang.biao@linux.dev Subject: [PATCH RFC bpf-next 1/3] bpf: report probe fault to BPF stderr Date: Sat, 27 Sep 2025 14:12:08 +0800 Message-ID: <20250927061210.194502-2-menglong.dong@linux.dev> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250927061210.194502-1-menglong.dong@linux.dev> References: <20250927061210.194502-1-menglong.dong@linux.dev> 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" Introduce the function bpf_prog_report_probe_violation(), which is used to report the memory probe fault to the user by the BPF stderr. Signed-off-by: Menglong Dong --- include/linux/bpf.h | 1 + kernel/trace/bpf_trace.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 6338e54a9b1f..a31c5ce56c32 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2902,6 +2902,7 @@ void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, voi= d *data, void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr); void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr); void bpf_prog_report_arena_violation(bool write, unsigned long addr, unsig= ned long fault_ip); +void bpf_prog_report_probe_violation(bool write, unsigned long fault_ip); =20 #else /* !CONFIG_BPF_SYSCALL */ static inline struct bpf_prog *bpf_prog_get(u32 ufd) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 8f23f5273bab..9bd03a9f53db 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2055,6 +2055,24 @@ void bpf_put_raw_tracepoint(struct bpf_raw_event_map= *btp) module_put(mod); } =20 +void bpf_prog_report_probe_violation(bool write, unsigned long fault_ip) +{ + struct bpf_stream_stage ss; + struct bpf_prog *prog; + + rcu_read_lock(); + prog =3D bpf_prog_ksym_find(fault_ip); + rcu_read_unlock(); + if (!prog) + return; + + bpf_stream_stage(ss, prog, BPF_STDERR, ({ + bpf_stream_printk(ss, "ERROR: Probe %s access faule, insn=3D0x%lx\n", + write ? "WRITE" : "READ", fault_ip); + bpf_stream_dump_stack(ss); + })); +} + static __always_inline void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) { --=20 2.51.0