[PATCH bpf-next] bpf: Fix bpf_prog_test_run_tracing for !CONFIG_NET

[KP Singh]

From: KP Singh <kpsingh at google.com>

test_run.o is not built when CONFIG_NET is not set and
bpf_prog_test_run_tracing being referenced in bpf_trace.o causes the
linker error:

ld: kernel/trace/bpf_trace.o:(.rodata+0x38): undefined reference to
 `bpf_prog_test_run_tracing'

Add a __weak function in bpf_trace.c to handle this.

Fixes: da00d2f117a0 ("bpf: Add test ops for BPF_PROG_TYPE_TRACING")
Signed-off-by: KP Singh <kpsingh at google.com>
---
 kernel/trace/bpf_trace.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 363e0a2c75cf..6a490d8ce9de 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1252,6 +1252,13 @@ static bool tracing_prog_is_valid_access(int off, int size,
 	return btf_ctx_access(off, size, type, prog, info);
 }
 
+int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
+				     const union bpf_attr *kattr,
+				     union bpf_attr __user *uattr)
+{
+	return -ENOTSUPP;
+}
+
 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
 	.get_func_proto  = raw_tp_prog_func_proto,
 	.is_valid_access = raw_tp_prog_is_valid_access,
-- 
2.20.1