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authorAndrii Nakryiko <andrii@kernel.org>2020-12-03 12:46:21 -0800
committerAlexei Starovoitov <ast@kernel.org>2020-12-03 17:38:20 -0800
commit12cc126df82c96c89706aa207ad27c56f219047c (patch)
tree481eb62be58a08f279c73fd34f2d9f9f16c786af /kernel/trace
parentcadd64807cd83e2213dcb70f93d12d978c02b5fa (diff)
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: a38d1107f937 ("bpf: support raw tracepoints in modules") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201203204634.1325171-2-andrii@kernel.org
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/bpf_trace.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d255bc9b2bfa..23a390aac524 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -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