selftests/bpf: Adapt assert_mprog_count to always expect 0 count

Simplify __assert_mprog_count() to remove the -ENOENT corner case as the
bpf_prog_query() now returns 0 when no bpf_mprog is attached. This also
allows to convert a few test cases from using raw __assert_mprog_count()
over to plain assert_mprog_count() helper.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20231006220655.1653-5-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Author: borkmann

tools/testing/selftests/bpf/prog_tests/tc_helpers.h

@@ -45,28 +45,25 @@ static inline __u32 ifindex_from_link_fd(int fd)
 	return link_info.tcx.ifindex;
 }
 
-static inline void __assert_mprog_count(int target, int expected, bool miniq, int ifindex)
+static inline void __assert_mprog_count(int target, int expected, int ifindex)
 {
 	__u32 count = 0, attach_flags = 0;
 	int err;
 
 	err = bpf_prog_query(ifindex, target, 0, &attach_flags,
 			     NULL, &count);
 	ASSERT_EQ(count, expected, "count");
-	if (!expected && !miniq)
-		ASSERT_EQ(err, -ENOENT, "prog_query");
-	else
-		ASSERT_EQ(err, 0, "prog_query");
+	ASSERT_EQ(err, 0, "prog_query");
 }
 
 static inline void assert_mprog_count(int target, int expected)
 {
-	__assert_mprog_count(target, expected, false, loopback);
+	__assert_mprog_count(target, expected, loopback);
 }
 
 static inline void assert_mprog_count_ifindex(int ifindex, int target, int expected)
 {
-	__assert_mprog_count(target, expected, false, ifindex);
+	__assert_mprog_count(target, expected, ifindex);
 }
 
 #endif /* TC_HELPERS */

tools/testing/selftests/bpf/prog_tests/tc_links.c

@@ -1667,7 +1667,7 @@ static void test_tc_chain_mixed(int target)
 	if (!ASSERT_OK(err, "prog_detach"))
 		goto cleanup;
 
-	__assert_mprog_count(target, 0, true, loopback);
+	assert_mprog_count(target, 0);
 
 	ASSERT_OK(system(ping_cmd), ping_cmd);
 

tools/testing/selftests/bpf/prog_tests/tc_opts.c

@@ -635,7 +635,7 @@ static void test_tc_chain_classic(int target, bool chain_tc_old)
 	if (!ASSERT_OK(err, "prog_detach"))
 		goto cleanup;
 
-	__assert_mprog_count(target, 0, chain_tc_old, loopback);
+	assert_mprog_count(target, 0);
 cleanup:
 	if (tc_attached) {
 		tc_opts.flags = tc_opts.prog_fd = tc_opts.prog_id = 0;
@@ -2250,7 +2250,7 @@ static void test_tc_opts_delete_empty(int target, bool chain_tc_old)
 				       BPF_TC_INGRESS : BPF_TC_EGRESS;
 		err = bpf_tc_hook_create(&tc_hook);
 		ASSERT_OK(err, "bpf_tc_hook_create");
-		__assert_mprog_count(target, 0, true, loopback);
+		assert_mprog_count(target, 0);
 	}
 	err = bpf_prog_detach_opts(0, loopback, target, &optd);
 	ASSERT_EQ(err, -ENOENT, "prog_detach");
@@ -2352,7 +2352,7 @@ static void test_tc_chain_mixed(int target)
 cleanup_opts:
 	err = bpf_prog_detach_opts(detach_fd, loopback, target, &optd);
 	ASSERT_OK(err, "prog_detach");
-	__assert_mprog_count(target, 0, true, loopback);
+	assert_mprog_count(target, 0);
 
 	ASSERT_OK(system(ping_cmd), ping_cmd);