diff mbox series

[bpf,2/2] bpf: Set and check spin lock value in sk_storage_map_test

Message ID 20221114134720.1057939-3-xukuohai@huawei.com
State Accepted
Commit d59d3b8a3ed1d9006c602d991d52b351ed851180
Headers show
Series Bug fix and test case for special map value field | expand

Commit Message

Xu Kuohai Nov. 14, 2022, 1:47 p.m. UTC 
Update sk_storage_map_test to make sure kernel does not copy user
non-zero value spin lock to kernel, and does not copy kernel spin
lock value to user.

If user spin lock value is copied to kernel, this test case will
make kernel spin on the copied lock, resulting in rcu stall and
softlockup.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
---
 .../selftests/bpf/map_tests/sk_storage_map.c  | 36 ++++++++++---------
 1 file changed, 20 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/map_tests/sk_storage_map.c b/tools/testing/selftests/bpf/map_tests/sk_storage_map.c
index 099eb4dfd4f7..18405c3b7cee 100644
--- a/tools/testing/selftests/bpf/map_tests/sk_storage_map.c
+++ b/tools/testing/selftests/bpf/map_tests/sk_storage_map.c
@@ -458,7 +458,7 @@  static void test_sk_storage_map_basic(void)
 	struct {
 		int cnt;
 		int lock;
-	} value = { .cnt = 0xeB9f, .lock = 0, }, lookup_value;
+	} value = { .cnt = 0xeB9f, .lock = 1, }, lookup_value;
 	struct bpf_map_create_opts bad_xattr;
 	int btf_fd, map_fd, sk_fd, err;
 
@@ -483,38 +483,41 @@  static void test_sk_storage_map_basic(void)
 	      "err:%d errno:%d\n", err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Bump the cnt and update with BPF_EXIST | BPF_F_LOCK */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value,
 				  BPF_EXIST | BPF_F_LOCK);
 	CHECK(err, "bpf_map_update_elem(BPF_EXIST|BPF_F_LOCK)",
 	      "err:%d errno:%d\n", err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Bump the cnt and update with BPF_EXIST */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value, BPF_EXIST);
 	CHECK(err, "bpf_map_update_elem(BPF_EXIST)",
 	      "err:%d errno:%d\n", err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Update with BPF_NOEXIST */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value,
 				  BPF_NOEXIST | BPF_F_LOCK);
 	CHECK(!err || errno != EEXIST,
@@ -526,22 +529,23 @@  static void test_sk_storage_map_basic(void)
 	value.cnt -= 1;
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Bump the cnt again and update with map_flags == 0 */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value, 0);
 	CHECK(err, "bpf_map_update_elem()", "err:%d errno:%d\n",
 	      err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Test delete elem */
 	err = bpf_map_delete_elem(map_fd, &sk_fd);