[PATCH bpf-next 1/6] bpf: fix bpf_put_raw_tracepoint()'s use of __module_address()

[Andrii Nakryiko]

__module_address() needs to be called with preemption disabled or with
module_mutex taken. preempt_disable() is enough for read-only uses, which is
what this fix does.

Fixes: a38d1107f937 ("bpf: support raw tracepoints in modules")
Signed-off-by: Andrii Nakryiko <and...@kernel.org>
---
 kernel/trace/bpf_trace.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d255bc9b2bfa..bb98a377050a 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2060,7 +2060,11 @@ struct bpf_raw_event_map *bpf_get_raw_tracepoint(const 
char *name)
 
 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
 {
-       struct module *mod = __module_address((unsigned long)btp);
+       struct module *mod;
+
+       preempt_disable();
+       mod = __module_address((unsigned long)btp);
+       preempt_enable();
 
        if (mod)
                module_put(mod);
-- 
2.24.1