__module_address() can be invoked within a RCU section, there is no requirement to have preemption disabled.
Replace the preempt_disable() section around __module_address() with RCU. Cc: Alexei Starovoitov <[email protected]> Cc: Andrii Nakryiko <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: Eduard Zingerman <[email protected]> Cc: Hao Luo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: John Fastabend <[email protected]> Cc: KP Singh <[email protected]> Cc: Martin KaFai Lau <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Matt Bobrowski <[email protected]> Cc: Song Liu <[email protected]> Cc: Stanislav Fomichev <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Yonghong Song <[email protected]> Cc: [email protected] Cc: [email protected] Acked-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Sebastian Andrzej Siewior <[email protected]> --- kernel/trace/bpf_trace.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 1b8db5aee9d38..020df7b6ff90c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2336,10 +2336,9 @@ void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) { struct module *mod; - preempt_disable(); + guard(rcu)(); mod = __module_address((unsigned long)btp); module_put(mod); - preempt_enable(); } static __always_inline @@ -2907,16 +2906,14 @@ static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u3 for (i = 0; i < addrs_cnt; i++) { struct module *mod; - preempt_disable(); - mod = __module_address(addrs[i]); - /* Either no module or we it's already stored */ - if (!mod || has_module(&arr, mod)) { - preempt_enable(); - continue; + scoped_guard(rcu) { + mod = __module_address(addrs[i]); + /* Either no module or we it's already stored */ + if (!mod || has_module(&arr, mod)) + continue; + if (!try_module_get(mod)) + err = -EINVAL; } - if (!try_module_get(mod)) - err = -EINVAL; - preempt_enable(); if (err) break; err = add_module(&arr, mod); -- 2.47.1
