Re: [PATCH net] vsock/test: fix send_buf()/recv_buf() EINTR handling

[Luigi Leonardi]

On Fri, Apr 03, 2026 at 11:32:51AM +0200, Stefano Garzarella wrote:
> From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
>
> When send() or recv() returns -1 with errno == EINTR, the code skips
> the break but still adds the return value to nwritten/nread, making it
> decrease by 1. This leads to wrong buffer offsets and wrong bytes count.
>
> Fix it by explicitly continuing the loop on EINTR, so the return value
> is only added when it is positive.
>
> Fixes: a8ed71a27ef5 ("vsock/test: add recv_buf() utility function")
> Fixes: 12329bd51fdc ("vsock/test: add send_buf() utility function")
> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> ---
> tools/testing/vsock/util.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c
> index 9430ef5b8bc3..1fe1338c79cd 100644
> --- a/tools/testing/vsock/util.c
> +++ b/tools/testing/vsock/util.c
> @@ -344,7 +344,9 @@ void send_buf(int fd, const void *buf, size_t len, int flags,
> 		ret = send(fd, buf + nwritten, len - nwritten, flags);
> 		timeout_check("send");
>
> -		if (ret == 0 || (ret < 0 && errno != EINTR))
> +		if (ret < 0 && errno == EINTR)
> +			continue;
> +		if (ret <= 0)
> 			break;
>
> 		nwritten += ret;
> @@ -396,7 +398,9 @@ void recv_buf(int fd, void *buf, size_t len, int flags, ssize_t expected_ret)
> 		ret = recv(fd, buf + nread, len - nread, flags);
> 		timeout_check("recv");
>
> -		if (ret == 0 || (ret < 0 && errno != EINTR))
> +		if (ret < 0 && errno == EINTR)
> +			continue;
> +		if (ret <= 0)
> 			break;
>
> 		nread += ret;
> --
> 2.53.0

LGTM!

Reviewed-by: Luigi Leonardi <leonardi@xxxxxxxxxx>