Re: [PATCH net v1] vsock/test: fix SEQPACKET message bounds test

[Stefano Garzarella]

On Wed, Nov 22, 2023 at 12:16:42AM +0300, Arseniy Krasnov wrote:
> Tune message length calculation to make this test work on machines
> where 'getpagesize()' returns >32KB. Now maximum message length is not
> hardcoded (on machines above it was smaller than 'getpagesize()' return
> value, thus we get negative value and test fails), but calculated at
> runtime and always bigger than 'getpagesize()' result. Reproduced on
> aarch64 with 64KB page size.

It was reported to me by Bogdan, so we can add:

Reported-by: Bogdan Marcynkov <bmarcynk@xxxxxxxxxx>

> Fixes: 5c338112e48a ("test/vsock: rework message bounds test")
> Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
> ---
> tools/testing/vsock/vsock_test.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)

The fix LGTM and it worked on aarch64 machine.

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>

Thanks for the fast fix!
Stefano

> diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
> index f5623b8d76b7..691e44c746bf 100644
> --- a/tools/testing/vsock/vsock_test.c
> +++ b/tools/testing/vsock/vsock_test.c
> @@ -353,11 +353,12 @@ static void test_stream_msg_peek_server(const struct test_opts *opts)
> }
>
> #define SOCK_BUF_SIZE (2 * 1024 * 1024)
> -#define MAX_MSG_SIZE (32 * 1024)
> +#define MAX_MSG_PAGES 4
>
> static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
> {
> 	unsigned long curr_hash;
> +	size_t max_msg_size;
> 	int page_size;
> 	int msg_count;
> 	int fd;
> @@ -373,7 +374,8 @@ static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
>
> 	curr_hash = 0;
> 	page_size = getpagesize();
> -	msg_count = SOCK_BUF_SIZE / MAX_MSG_SIZE;
> +	max_msg_size = MAX_MSG_PAGES * page_size;
> +	msg_count = SOCK_BUF_SIZE / max_msg_size;
>
> 	for (int i = 0; i < msg_count; i++) {
> 		size_t buf_size;
> @@ -383,7 +385,7 @@ static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
> 		/* Use "small" buffers and "big" buffers. */
> 		if (i & 1)
> 			buf_size = page_size +
> -					(rand() % (MAX_MSG_SIZE - page_size));
> +					(rand() % (max_msg_size - page_size));
> 		else
> 			buf_size = 1 + (rand() % page_size);
>
> @@ -429,7 +431,6 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
> 	unsigned long remote_hash;
> 	unsigned long curr_hash;
> 	int fd;
> -	char buf[MAX_MSG_SIZE];
> 	struct msghdr msg = {0};
> 	struct iovec iov = {0};
>
> @@ -457,8 +458,13 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
> 	control_writeln("SRVREADY");
> 	/* Wait, until peer sends whole data. */
> 	control_expectln("SENDDONE");
> -	iov.iov_base = buf;
> -	iov.iov_len = sizeof(buf);
> +	iov.iov_len = MAX_MSG_PAGES * getpagesize();
> +	iov.iov_base = malloc(iov.iov_len);
> +	if (!iov.iov_base) {
> +		perror("malloc");
> +		exit(EXIT_FAILURE);
> +	}
> +
> 	msg.msg_iov = &iov;
> 	msg.msg_iovlen = 1;
>
> @@ -483,6 +489,7 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
> 		curr_hash += hash_djb2(msg.msg_iov[0].iov_base, recv_size);
> 	}
>
> +	free(iov.iov_base);
> 	close(fd);
> 	remote_hash = control_readulong();
>
> --
> 2.25.1