bpf_tcp_ca uses the `CHECK` calls even though the use of
ASSERT_ series of macros is preferred in the bpf selftests.

This patch replaces all `CHECK` calls for equivalent `ASSERT_`
macro calls.

Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
---
 .../selftests/bpf/prog_tests/bpf_tcp_ca.c     | 50 +++++++++----------
 1 file changed, 23 insertions(+), 27 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 4aabeaa525d4..6d610b66ec38 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
@@ -20,15 +20,14 @@
 
 static const unsigned int total_bytes = 10 * 1024 * 1024;
 static int expected_stg = 0xeB9F;
-static int stop, duration;
+static int stop;
 
 static int settcpca(int fd, const char *tcp_ca)
 {
 	int err;
 
 	err = setsockopt(fd, IPPROTO_TCP, TCP_CONGESTION, tcp_ca, strlen(tcp_ca));
-	if (CHECK(err == -1, "setsockopt(fd, TCP_CONGESTION)", "errno:%d\n",
-		  errno))
+	if (!ASSERT_NEQ(err, -1, "setsockopt"))
 		return -1;
 
 	return 0;
@@ -65,8 +64,7 @@ static void *server(void *arg)
 		bytes += nr_sent;
 	}
 
-	CHECK(bytes != total_bytes, "send", "%zd != %u nr_sent:%zd errno:%d\n",
-	      bytes, total_bytes, nr_sent, errno);
+	ASSERT_EQ(bytes, total_bytes, "send");
 
 done:
 	if (fd >= 0)
@@ -92,10 +90,11 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 	WRITE_ONCE(stop, 0);
 
 	lfd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (CHECK(lfd == -1, "socket", "errno:%d\n", errno))
+	if (!ASSERT_NEQ(lfd, -1, "socket"))
 		return;
+
 	fd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (CHECK(fd == -1, "socket", "errno:%d\n", errno)) {
+	if (!ASSERT_NEQ(fd, -1, "socket")) {
 		close(lfd);
 		return;
 	}
@@ -108,26 +107,27 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 	sa6.sin6_family = AF_INET6;
 	sa6.sin6_addr = in6addr_loopback;
 	err = bind(lfd, (struct sockaddr *)&sa6, addrlen);
-	if (CHECK(err == -1, "bind", "errno:%d\n", errno))
+	if (!ASSERT_NEQ(err, -1, "bind"))
 		goto done;
+
 	err = getsockname(lfd, (struct sockaddr *)&sa6, &addrlen);
-	if (CHECK(err == -1, "getsockname", "errno:%d\n", errno))
+	if (!ASSERT_NEQ(err, -1, "getsockname"))
 		goto done;
+
 	err = listen(lfd, 1);
-	if (CHECK(err == -1, "listen", "errno:%d\n", errno))
+	if (!ASSERT_NEQ(err, -1, "listen"))
 		goto done;
 
 	if (sk_stg_map) {
 		err = bpf_map_update_elem(bpf_map__fd(sk_stg_map), &fd,
 					  &expected_stg, BPF_NOEXIST);
-		if (CHECK(err, "bpf_map_update_elem(sk_stg_map)",
-			  "err:%d errno:%d\n", err, errno))
+		if (!ASSERT_OK(err, "bpf_map_update_elem(sk_stg_map)"))
 			goto done;
 	}
 
 	/* connect to server */
 	err = connect(fd, (struct sockaddr *)&sa6, addrlen);
-	if (CHECK(err == -1, "connect", "errno:%d\n", errno))
+	if (!ASSERT_NEQ(err, -1, "connect"))
 		goto done;
 
 	if (sk_stg_map) {
@@ -135,14 +135,13 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 
 		err = bpf_map_lookup_elem(bpf_map__fd(sk_stg_map), &fd,
 					  &tmp_stg);
-		if (CHECK(!err || errno != ENOENT,
-			  "bpf_map_lookup_elem(sk_stg_map)",
-			  "err:%d errno:%d\n", err, errno))
+		if (!ASSERT_NEQ(err, 0, "bpf_map_lookup_elem(sk_stg_map)") ||
+				!ASSERT_EQ(errno, ENOENT, "bpf_map_lookup_elem(sk_stg_map)"))
 			goto done;
 	}
 
 	err = pthread_create(&srv_thread, NULL, server, (void *)(long)lfd);
-	if (CHECK(err != 0, "pthread_create", "err:%d errno:%d\n", err, errno))
+	if (!ASSERT_OK(err, "pthread_create"))
 		goto done;
 
 	/* recv total_bytes */
@@ -156,13 +155,12 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 		bytes += nr_recv;
 	}
 
-	CHECK(bytes != total_bytes, "recv", "%zd != %u nr_recv:%zd errno:%d\n",
-	      bytes, total_bytes, nr_recv, errno);
+	ASSERT_EQ(bytes, total_bytes, "recv");
 
 	WRITE_ONCE(stop, 1);
-	pthread_join(srv_thread, &thread_ret);
-	CHECK(IS_ERR(thread_ret), "pthread_join", "thread_ret:%ld",
-	      PTR_ERR(thread_ret));
+	err = pthread_join(srv_thread, &thread_ret);
+	ASSERT_OK(err, "pthread_join");
+
 done:
 	close(lfd);
 	close(fd);
@@ -174,7 +172,7 @@ static void test_cubic(void)
 	struct bpf_link *link;
 
 	cubic_skel = bpf_cubic__open_and_load();
-	if (CHECK(!cubic_skel, "bpf_cubic__open_and_load", "failed\n"))
+	if (!ASSERT_OK_PTR(cubic_skel, "bpf_cubic__open_and_load"))
 		return;
 
 	link = bpf_map__attach_struct_ops(cubic_skel->maps.cubic);
@@ -197,7 +195,7 @@ static void test_dctcp(void)
 	struct bpf_link *link;
 
 	dctcp_skel = bpf_dctcp__open_and_load();
-	if (CHECK(!dctcp_skel, "bpf_dctcp__open_and_load", "failed\n"))
+	if (!ASSERT_OK_PTR(dctcp_skel, "bpf_dctcp__open_and_load"))
 		return;
 
 	link = bpf_map__attach_struct_ops(dctcp_skel->maps.dctcp);
@@ -207,9 +205,7 @@ static void test_dctcp(void)
 	}
 
 	do_test("bpf_dctcp", dctcp_skel->maps.sk_stg_map);
-	CHECK(dctcp_skel->bss->stg_result != expected_stg,
-	      "Unexpected stg_result", "stg_result (%x) != expected_stg (%x)\n",
-	      dctcp_skel->bss->stg_result, expected_stg);
+	ASSERT_EQ(dctcp_skel->bss->stg_result, expected_stg, "stg_result");
 
 	bpf_link__destroy(link);
 	bpf_dctcp__destroy(dctcp_skel);
-- 
2.25.1

On 11/18/23 1:42 PM, Yuran Pereira wrote:
> bpf_tcp_ca uses the `CHECK` calls even though the use of
> ASSERT_ series of macros is preferred in the bpf selftests.
>
> This patch replaces all `CHECK` calls for equivalent `ASSERT_`
> macro calls.
>
> Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
> ---
>   .../selftests/bpf/prog_tests/bpf_tcp_ca.c     | 50 +++++++++----------
>   1 file changed, 23 insertions(+), 27 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 4aabeaa525d4..6d610b66ec38 100644
> --- a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> @@ -20,15 +20,14 @@
>   
>   static const unsigned int total_bytes = 10 * 1024 * 1024;
>   static int expected_stg = 0xeB9F;
> -static int stop, duration;
> +static int stop;
>   
> [...]
> @@ -108,26 +107,27 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
>   	sa6.sin6_family = AF_INET6;
>   	sa6.sin6_addr = in6addr_loopback;
>   	err = bind(lfd, (struct sockaddr *)&sa6, addrlen);
> -	if (CHECK(err == -1, "bind", "errno:%d\n", errno))
> +	if (!ASSERT_NEQ(err, -1, "bind"))
>   		goto done;
> +
>   	err = getsockname(lfd, (struct sockaddr *)&sa6, &addrlen);
> -	if (CHECK(err == -1, "getsockname", "errno:%d\n", errno))
> +	if (!ASSERT_NEQ(err, -1, "getsockname"))
>   		goto done;
> +
>   	err = listen(lfd, 1);
> -	if (CHECK(err == -1, "listen", "errno:%d\n", errno))
> +	if (!ASSERT_NEQ(err, -1, "listen"))
>   		goto done;
>   
>   	if (sk_stg_map) {
>   		err = bpf_map_update_elem(bpf_map__fd(sk_stg_map), &fd,
>   					  &expected_stg, BPF_NOEXIST);
> -		if (CHECK(err, "bpf_map_update_elem(sk_stg_map)",
> -			  "err:%d errno:%d\n", err, errno))
> +		if (!ASSERT_OK(err, "bpf_map_update_elem(sk_stg_map)"))
>   			goto done;
>   	}
>   
>   	/* connect to server */
>   	err = connect(fd, (struct sockaddr *)&sa6, addrlen);
> -	if (CHECK(err == -1, "connect", "errno:%d\n", errno))
> +	if (!ASSERT_NEQ(err, -1, "connect"))
>   		goto done;
>   
>   	if (sk_stg_map) {
> @@ -135,14 +135,13 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
>   
>   		err = bpf_map_lookup_elem(bpf_map__fd(sk_stg_map), &fd,
>   					  &tmp_stg);
> -		if (CHECK(!err || errno != ENOENT,
> -			  "bpf_map_lookup_elem(sk_stg_map)",
> -			  "err:%d errno:%d\n", err, errno))
> +		if (!ASSERT_NEQ(err, 0, "bpf_map_lookup_elem(sk_stg_map)") ||

!ASSERT_ERR(err, "bpf_map_lookup_elem(sk_stg_map)")
might be simpler than !ASSERT_NEQ(..).

> +				!ASSERT_EQ(errno, ENOENT, "bpf_map_lookup_elem(sk_stg_map)"))
>   			goto done;
>   	}
>   
>   	err = pthread_create(&srv_thread, NULL, server, (void *)(long)lfd);
> -	if (CHECK(err != 0, "pthread_create", "err:%d errno:%d\n", err, errno))
> +	if (!ASSERT_OK(err, "pthread_create"))
>   		goto done;
>   
>   	/* recv total_bytes */
> @@ -156,13 +155,12 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
>   		bytes += nr_recv;
>   	}
>   
> -	CHECK(bytes != total_bytes, "recv", "%zd != %u nr_recv:%zd errno:%d\n",
> -	      bytes, total_bytes, nr_recv, errno);
> +	ASSERT_EQ(bytes, total_bytes, "recv");
>   
>   	WRITE_ONCE(stop, 1);
> -	pthread_join(srv_thread, &thread_ret);
> -	CHECK(IS_ERR(thread_ret), "pthread_join", "thread_ret:%ld",
> -	      PTR_ERR(thread_ret));
> +	err = pthread_join(srv_thread, &thread_ret);
> +	ASSERT_OK(err, "pthread_join");

The above is not equivalent to the original code.
The original didn't check pthread_join() return as it
is very very unlikely to fail. And check 'thread_ret'
is still needed.

> +
>   done:
>   	close(lfd);
>   	close(fd);
> @@ -174,7 +172,7 @@ static void test_cubic(void)
>   	struct bpf_link *link;
>   
>   	cubic_skel = bpf_cubic__open_and_load();
> -	if (CHECK(!cubic_skel, "bpf_cubic__open_and_load", "failed\n"))
> +	if (!ASSERT_OK_PTR(cubic_skel, "bpf_cubic__open_and_load"))
>   		return;

[...]

Hello Yonghong,
On Mon, Nov 20, 2023 at 07:22:59AM -0800, Yonghong Song wrote:
> > -		if (CHECK(!err || errno != ENOENT,
> > -			  "bpf_map_lookup_elem(sk_stg_map)",
> > -			  "err:%d errno:%d\n", err, errno))
> > +		if (!ASSERT_NEQ(err, 0, "bpf_map_lookup_elem(sk_stg_map)") ||
> 
> !ASSERT_ERR(err, "bpf_map_lookup_elem(sk_stg_map)")
> might be simpler than !ASSERT_NEQ(..).
> 
Sure, that makes sense. I'll change it in v3.
> > -	pthread_join(srv_thread, &thread_ret);
> > -	CHECK(IS_ERR(thread_ret), "pthread_join", "thread_ret:%ld",
> > -	      PTR_ERR(thread_ret));
> > +	err = pthread_join(srv_thread, &thread_ret);
> > +	ASSERT_OK(err, "pthread_join");
> 
> The above is not equivalent to the original code.
> The original didn't check pthread_join() return as it
> is very very unlikely to fail. And check 'thread_ret'
> is still needed.
> 
Yes that is true, but the v1 [1] broke the tests because the
ASSERT_OK_PTR(thread_ret, "pthread_join") kept failing, even
though all the asserts within the `server()` function itself
passed.

Also, isn't asserting `thread_ret` technically checking the
`server()` function instead of `pthread_join`? So should we
have two asserts here? One for `server` and one for `pthread_join`
or is it not necessary?
i.e:
```
ASSERT_OK_PTR(thread_ret, "server");
ASSERT_OK(err, "pthread_join");
```

Upon taking a second look, I now think that the reason why
`ASSERT_OK_PTR(thread_ret, "pthread_join");` failed in v1 might
have been because it calls `libbpf_get_error` which returns
`-errno` when the pointer is `NULL`.

Since `server`'s return value is not a bpf address, which
`ASSERT_OK_PTR` expects it to be, do you that think we should
explicitly set `errno = 0` prior to returning NULL on server?
That way that assert would pass even when the pointer is NULL
(which is the case when `server` returns successfuly).

[1] - https://lore.kernel.org/lkml/GV1PR10MB6563A0BE91080E6E8EC2651DE8B0A@GV1PR10MB6563.EURPRD10.PROD.OUTLOOK.COM/

As always, thank you for your feedback.

Yuran Pereira

On 11/20/23 12:15 PM, Yuran Pereira wrote:
> Hello Yonghong,
> On Mon, Nov 20, 2023 at 07:22:59AM -0800, Yonghong Song wrote:
>>> -		if (CHECK(!err || errno != ENOENT,
>>> -			  "bpf_map_lookup_elem(sk_stg_map)",
>>> -			  "err:%d errno:%d\n", err, errno))
>>> +		if (!ASSERT_NEQ(err, 0, "bpf_map_lookup_elem(sk_stg_map)") ||
>> !ASSERT_ERR(err, "bpf_map_lookup_elem(sk_stg_map)")
>> might be simpler than !ASSERT_NEQ(..).
>>
> Sure, that makes sense. I'll change it in v3.
>>> -	pthread_join(srv_thread, &thread_ret);
>>> -	CHECK(IS_ERR(thread_ret), "pthread_join", "thread_ret:%ld",
>>> -	      PTR_ERR(thread_ret));
>>> +	err = pthread_join(srv_thread, &thread_ret);
>>> +	ASSERT_OK(err, "pthread_join");
>> The above is not equivalent to the original code.
>> The original didn't check pthread_join() return as it
>> is very very unlikely to fail. And check 'thread_ret'
>> is still needed.
>>
> Yes that is true, but the v1 [1] broke the tests because the
> ASSERT_OK_PTR(thread_ret, "pthread_join") kept failing, even
> though all the asserts within the `server()` function itself
> passed.
>
> Also, isn't asserting `thread_ret` technically checking the
> `server()` function instead of `pthread_join`? So should we
> have two asserts here? One for `server` and one for `pthread_join`
> or is it not necessary?
> i.e:
> ```
> ASSERT_OK_PTR(thread_ret, "server");
> ASSERT_OK(err, "pthread_join");
> ```

As I mentioned, checking return value of pthread_join()
is not critical as in general pthread_join() not fail.
The test is not to test pthread_join() and if pthread_join()
fails it would be an even bigger problem affecting many other
tests.

>
> Upon taking a second look, I now think that the reason why
> `ASSERT_OK_PTR(thread_ret, "pthread_join");` failed in v1 might
> have been because it calls `libbpf_get_error` which returns
> `-errno` when the pointer is `NULL`.
>
> Since `server`'s return value is not a bpf address, which
> `ASSERT_OK_PTR` expects it to be, do you that think we should
> explicitly set `errno = 0` prior to returning NULL on server?
> That way that assert would pass even when the pointer is NULL
> (which is the case when `server` returns successfuly).

Let us just do

   ASSERT_OK(IS_ERR(thread_ret), "thread_ret")


>
> [1] - https://lore.kernel.org/lkml/GV1PR10MB6563A0BE91080E6E8EC2651DE8B0A@GV1PR10MB6563.EURPRD10.PROD.OUTLOOK.COM/
>
> As always, thank you for your feedback.
>
> Yuran Pereira
>