selftests/bpf: Rename fallback in bpf_dctcp to avoid naming conflict

Recently, when compiling bpf selftests on RV64, the following
compilation failure occurred:

progs/bpf_dctcp.c:29:21: error: redefinition of 'fallback' as different kind of symbol
   29 | volatile const char fallback[TCP_CA_NAME_MAX];
      |                     ^
/workspace/tools/testing/selftests/bpf/tools/include/vmlinux.h:86812:15: note: previous definition is here
 86812 | typedef u32 (*fallback)(u32, const unsigned char *, size_t);

The reason is that the `fallback` symbol has been defined in
arch/riscv/lib/crc32.c, which will cause symbol conflicts when vmlinux.h
is included in bpf_dctcp. Let we rename `fallback` string to
`fallback_cc` in bpf_dctcp to fix this compilation failure.

Signed-off-by: Pu Lehui <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
index 1d494b4453f4..409a06975823 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
@@ -285,7 +285,7 @@ static void test_dctcp_fallback(void)
 	dctcp_skel = bpf_dctcp__open();
 	if (!ASSERT_OK_PTR(dctcp_skel, "dctcp_skel"))
 		return;
-	strcpy(dctcp_skel->rodata->fallback, "cubic");
+	strcpy(dctcp_skel->rodata->fallback_cc, "cubic");
 	if (!ASSERT_OK(bpf_dctcp__load(dctcp_skel), "bpf_dctcp__load"))
 		goto done;