[PATCH AUTOSEL 6.6 02/21] selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh

[PATCH AUTOSEL 6.6 02/21] selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh

[Sasha Levin]

From: "Alessandro Carminati (Red Hat)" <alessandro.carminati@gmail.com>

[ Upstream commit f803bcf9208a2540acb4c32bdc3616673169f490 ]

In some systems, the netcat server can incur in delay to start listening.
When this happens, the test can randomly fail in various points.
This is an example error message:

   # ip gre none gso
   # encap 192.168.1.1 to 192.168.1.2, type gre, mac none len 2000
   # test basic connectivity
   # Ncat: Connection refused.

The issue stems from a race condition between the netcat client and server.
The test author had addressed this problem by implementing a sleep, which
I have removed in this patch.
This patch introduces a function capable of sleeping for up to two seconds.
However, it can terminate the waiting period early if the port is reported
to be listening.

Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240314105911.213411-1-alessandro.carminati@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/test_tc_tunnel.sh | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh
index 910044f08908a..7989ec6084545 100755
--- a/tools/testing/selftests/bpf/test_tc_tunnel.sh
+++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh
@@ -72,7 +72,6 @@ cleanup() {
 server_listen() {
 	ip netns exec "${ns2}" nc "${netcat_opt}" -l "${port}" > "${outfile}" &
 	server_pid=$!
-	sleep 0.2
 }
 
 client_connect() {
@@ -93,6 +92,16 @@ verify_data() {
 	fi
 }
 
+wait_for_port() {
+	for i in $(seq 20); do
+		if ip netns exec "${ns2}" ss ${2:--4}OHntl | grep -q "$1"; then
+			return 0
+		fi
+		sleep 0.1
+	done
+	return 1
+}
+
 set -e
 
 # no arguments: automated test, run all
@@ -193,6 +202,7 @@ setup
 # basic communication works
 echo "test basic connectivity"
 server_listen
+wait_for_port ${port} ${netcat_opt}
 client_connect
 verify_data
 
@@ -204,6 +214,7 @@ ip netns exec "${ns1}" tc filter add dev veth1 egress \
 	section "encap_${tuntype}_${mac}"
 echo "test bpf encap without decap (expect failure)"
 server_listen
+wait_for_port ${port} ${netcat_opt}
 ! client_connect
 
 if [[ "$tuntype" =~ "udp" ]]; then
-- 
2.43.0

[PATCH AUTOSEL 6.6 03/21] selftests/bpf: Fix flaky test btf_map_in_map/lookup_update

[Sasha Levin]

From: Yonghong Song <yonghong.song@linux.dev>

[ Upstream commit 14bb1e8c8d4ad5d9d2febb7d19c70a3cf536e1e5 ]

Recently, I frequently hit the following test failure:

  [root@arch-fb-vm1 bpf]# ./test_progs -n 33/1
  test_lookup_update:PASS:skel_open 0 nsec
  [...]
  test_lookup_update:PASS:sync_rcu 0 nsec
  test_lookup_update:FAIL:map1_leak inner_map1 leaked!
  #33/1    btf_map_in_map/lookup_update:FAIL
  #33      btf_map_in_map:FAIL

In the test, after map is closed and then after two rcu grace periods,
it is assumed that map_id is not available to user space.

But the above assumption cannot be guaranteed. After zero or one
or two rcu grace periods in different siturations, the actual
freeing-map-work is put into a workqueue. Later on, when the work
is dequeued, the map will be actually freed.
See bpf_map_put() in kernel/bpf/syscall.c.

By using workqueue, there is no ganrantee that map will be actually
freed after a couple of rcu grace periods. This patch removed
such map leak detection and then the test can pass consistently.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240322061353.632136-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../selftests/bpf/prog_tests/btf_map_in_map.c | 26 +------------------
 1 file changed, 1 insertion(+), 25 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
index a8b53b8736f01..f66ceccd7029c 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
@@ -25,7 +25,7 @@ static void test_lookup_update(void)
 	int map1_fd, map2_fd, map3_fd, map4_fd, map5_fd, map1_id, map2_id;
 	int outer_arr_fd, outer_hash_fd, outer_arr_dyn_fd;
 	struct test_btf_map_in_map *skel;
-	int err, key = 0, val, i, fd;
+	int err, key = 0, val, i;
 
 	skel = test_btf_map_in_map__open_and_load();
 	if (CHECK(!skel, "skel_open", "failed to open&load skeleton\n"))
@@ -102,30 +102,6 @@ static void test_lookup_update(void)
 	CHECK(map1_id == 0, "map1_id", "failed to get ID 1\n");
 	CHECK(map2_id == 0, "map2_id", "failed to get ID 2\n");
 
-	test_btf_map_in_map__destroy(skel);
-	skel = NULL;
-
-	/* we need to either wait for or force synchronize_rcu(), before
-	 * checking for "still exists" condition, otherwise map could still be
-	 * resolvable by ID, causing false positives.
-	 *
-	 * Older kernels (5.8 and earlier) freed map only after two
-	 * synchronize_rcu()s, so trigger two, to be entirely sure.
-	 */
-	CHECK(kern_sync_rcu(), "sync_rcu", "failed\n");
-	CHECK(kern_sync_rcu(), "sync_rcu", "failed\n");
-
-	fd = bpf_map_get_fd_by_id(map1_id);
-	if (CHECK(fd >= 0, "map1_leak", "inner_map1 leaked!\n")) {
-		close(fd);
-		goto cleanup;
-	}
-	fd = bpf_map_get_fd_by_id(map2_id);
-	if (CHECK(fd >= 0, "map2_leak", "inner_map2 leaked!\n")) {
-		close(fd);
-		goto cleanup;
-	}
-
 cleanup:
 	test_btf_map_in_map__destroy(skel);
 }
-- 
2.43.0

[PATCH AUTOSEL 6.6 13/21] kselftest: arm64: Add a null pointer check

[Sasha Levin]

From: Kunwu Chan <chentao@kylinos.cn>

[ Upstream commit 80164282b3620a3cb73de6ffda5592743e448d0e ]

There is a 'malloc' call, which can be unsuccessful.
This patch will add the malloc failure checking
to avoid possible null dereference and give more information
about test fail reasons.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20240423082102.2018886-1-chentao@kylinos.cn
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/arm64/tags/tags_test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/arm64/tags/tags_test.c b/tools/testing/selftests/arm64/tags/tags_test.c
index 5701163460ef7..955f87c1170d7 100644
--- a/tools/testing/selftests/arm64/tags/tags_test.c
+++ b/tools/testing/selftests/arm64/tags/tags_test.c
@@ -6,6 +6,7 @@
 #include <stdint.h>
 #include <sys/prctl.h>
 #include <sys/utsname.h>
+#include "../../kselftest.h"
 
 #define SHIFT_TAG(tag)		((uint64_t)(tag) << 56)
 #define SET_TAG(ptr, tag)	(((uint64_t)(ptr) & ~SHIFT_TAG(0xff)) | \
@@ -21,6 +22,9 @@ int main(void)
 	if (prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) == 0)
 		tbi_enabled = 1;
 	ptr = (struct utsname *)malloc(sizeof(*ptr));
+	if (!ptr)
+		ksft_exit_fail_msg("Failed to allocate utsname buffer\n");
+
 	if (tbi_enabled)
 		tag = 0x42;
 	ptr = (struct utsname *)SET_TAG(ptr, tag);
-- 
2.43.0