[PATCH bpf-next v1 1/2] bpf: Allow bpf_res_spin_lock() in all contexts

[Kumar Kartikeya Dwivedi <memxor@gmail.com>]

There is no particular reason to keep bpf_res_spin_lock() disabled in
tracing programs, since it is safe against reentrancy and deadlocks.
Remove the restriction for tracing programs covered by the predicate
is_tracing_prog_type().

This is a prerequisite before the definition of is_tracing_prog_type()
is updated to include raw_tp, fentry, fexit, and fmod_ret. Existing
tracing programs will be updated to use bpf_res_spin_lock() instead when
it is available.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 kernel/bpf/verifier.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 52be0a118cce..57a76c21d624 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -17815,7 +17815,9 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 			verbose(env, "socket filter progs cannot use bpf_spin_lock yet\n");
 			return -EINVAL;
 		}
+	}
 
+	if (btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		if (is_tracing_prog_type(prog_type)) {
 			verbose(env, "tracing progs cannot use bpf_spin_lock yet\n");
 			return -EINVAL;
-- 
2.53.0