Commit 12cc126d authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov

bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()

__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. Also, module_put() does internal check for NULL, so drop
it as well.

Fixes: a38d1107 ("bpf: support raw tracepoints in modules")
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-2-andrii@kernel.org
parent cadd6480
......@@ -2060,10 +2060,12 @@ 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;
if (mod)
module_put(mod);
preempt_disable();
mod = __module_address((unsigned long)btp);
module_put(mod);
preempt_enable();
}
static __always_inline
......
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