[PATCH RFC bpf-next 1/3] bpf: report probe fault to BPF stderr
From: Menglong Dong <hidden>
Date: 2025-09-27 06:12:20
Also in:
bpf, lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [security & lsm] (security audit and enforcement using bpf), bpf [tracing], the rest, tracing · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, KP Singh, Matt Bobrowski, Song Liu, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
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 <redacted> --- 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, void *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, unsigned long fault_ip); +void bpf_prog_report_probe_violation(bool write, unsigned long fault_ip); #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); } +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 = 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=0x%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) {
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2.51.0