Re: [Qemu-devel] [PATCH] io: Fix double shift usages on QIOChannel features

["Marc-André Lureau" <mlureau@redhat.com>]

Hi

----- Original Message -----
> When QIOChannels were introduced in 666a3af9, the feature bits were
> defined shifted. However, when using them, the code was shifting them
> again. The incorrect use was consistent until 74b6ce43, where
> QIO_CHANNEL_FEATURE_LISTEN was defined shifted but tested unshifted.
> 

And by luck, QIO_CHANNEL_FEATURE_LISTEN == (1 << QIO_CHANNEL_FEATURE_LISTEN), so it works :)

> This patch fixes all uses of QIOChannel features. They are defined
> shifted and therefore set unshifted. It also makes all feature tests to
> use the qio_channel_has_feature() function.

Looks good, we may want to have it in -stable.

> 
> Signed-off-by: Felipe Franciosi <felipe@nutanix.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

> ---
>  io/channel-socket.c           |   11 ++++++-----
>  io/channel-tls.c              |    4 ++--
>  io/channel-websock.c          |    4 ++--
>  io/channel.c                  |   10 ++++------
>  migration/qemu-file-channel.c |    3 +--
>  qemu-char.c                   |    3 +--
>  6 files changed, 16 insertions(+), 19 deletions(-)
> 
> diff --git a/io/channel-socket.c b/io/channel-socket.c
> index 196a4f1..bb0a0a7 100644
> --- a/io/channel-socket.c
> +++ b/io/channel-socket.c
> @@ -55,7 +55,7 @@ qio_channel_socket_new(void)
>      sioc->fd = -1;
>  
>      ioc = QIO_CHANNEL(sioc);
> -    ioc->features |= (1 << QIO_CHANNEL_FEATURE_SHUTDOWN);
> +    ioc->features |= QIO_CHANNEL_FEATURE_SHUTDOWN;
>  
>  #ifdef WIN32
>      ioc->event = CreateEvent(NULL, FALSE, FALSE, NULL);
> @@ -107,12 +107,12 @@ qio_channel_socket_set_fd(QIOChannelSocket *sioc,
>  #ifndef WIN32
>      if (sioc->localAddr.ss_family == AF_UNIX) {
>          QIOChannel *ioc = QIO_CHANNEL(sioc);
> -        ioc->features |= (1 << QIO_CHANNEL_FEATURE_FD_PASS);
> +        ioc->features |= QIO_CHANNEL_FEATURE_FD_PASS;
>      }
>  #endif /* WIN32 */
>      if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &val, &len) == 0 && val) {
>          QIOChannel *ioc = QIO_CHANNEL(sioc);
> -        ioc->features |= (1 << QIO_CHANNEL_FEATURE_LISTEN);
> +        ioc->features |= QIO_CHANNEL_FEATURE_LISTEN;
>      }
>  
>      return 0;
> @@ -380,7 +380,7 @@ qio_channel_socket_accept(QIOChannelSocket *ioc,
>  
>  #ifndef WIN32
>      if (cioc->localAddr.ss_family == AF_UNIX) {
> -        QIO_CHANNEL(cioc)->features |= (1 << QIO_CHANNEL_FEATURE_FD_PASS);
> +        QIO_CHANNEL(cioc)->features |= QIO_CHANNEL_FEATURE_FD_PASS;
>      }
>  #endif /* WIN32 */
>  
> @@ -403,7 +403,8 @@ static void qio_channel_socket_finalize(Object *obj)
>      QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
>  
>      if (ioc->fd != -1) {
> -        if (QIO_CHANNEL(ioc)->features & QIO_CHANNEL_FEATURE_LISTEN) {
> +        if (qio_channel_has_feature(QIO_CHANNEL(ioc),
> +                                    QIO_CHANNEL_FEATURE_LISTEN)) {
>              Error *err = NULL;
>  
>              socket_listen_cleanup(ioc->fd, &err);
> diff --git a/io/channel-tls.c b/io/channel-tls.c
> index 9a8525c..d22996b 100644
> --- a/io/channel-tls.c
> +++ b/io/channel-tls.c
> @@ -111,8 +111,8 @@ qio_channel_tls_new_client(QIOChannel *master,
>      ioc = QIO_CHANNEL(tioc);
>  
>      tioc->master = master;
> -    if (master->features & (1 << QIO_CHANNEL_FEATURE_SHUTDOWN)) {
> -        ioc->features |= (1 << QIO_CHANNEL_FEATURE_SHUTDOWN);
> +    if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
> +        ioc->features |= QIO_CHANNEL_FEATURE_SHUTDOWN;
>      }
>      object_ref(OBJECT(master));
>  
> diff --git a/io/channel-websock.c b/io/channel-websock.c
> index 533bd4b..9accd16 100644
> --- a/io/channel-websock.c
> +++ b/io/channel-websock.c
> @@ -497,8 +497,8 @@ qio_channel_websock_new_server(QIOChannel *master)
>      ioc = QIO_CHANNEL(wioc);
>  
>      wioc->master = master;
> -    if (master->features & (1 << QIO_CHANNEL_FEATURE_SHUTDOWN)) {
> -        ioc->features |= (1 << QIO_CHANNEL_FEATURE_SHUTDOWN);
> +    if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
> +        ioc->features |= QIO_CHANNEL_FEATURE_SHUTDOWN;
>      }
>      object_ref(OBJECT(master));
>  
> diff --git a/io/channel.c b/io/channel.c
> index 923c465..ebe9f86 100644
> --- a/io/channel.c
> +++ b/io/channel.c
> @@ -23,13 +23,11 @@
>  #include "qapi/error.h"
>  #include "qemu/coroutine.h"
>  
> -bool qio_channel_has_feature(QIOChannel *ioc,
> -                             QIOChannelFeature feature)
> +bool qio_channel_has_feature(QIOChannel *ioc, QIOChannelFeature feature)
>  {
> -    return ioc->features & (1 << feature);
> +    return ioc->features & feature;
>  }
>  
> -
>  ssize_t qio_channel_readv_full(QIOChannel *ioc,
>                                 const struct iovec *iov,
>                                 size_t niov,
> @@ -40,7 +38,7 @@ ssize_t qio_channel_readv_full(QIOChannel *ioc,
>      QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
>  
>      if ((fds || nfds) &&
> -        !(ioc->features & (1 << QIO_CHANNEL_FEATURE_FD_PASS))) {
> +        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
>          error_setg_errno(errp, EINVAL,
>                           "Channel does not support file descriptor
>                           passing");
>          return -1;
> @@ -60,7 +58,7 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
>      QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
>  
>      if ((fds || nfds) &&
> -        !(ioc->features & (1 << QIO_CHANNEL_FEATURE_FD_PASS))) {
> +        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
>          error_setg_errno(errp, EINVAL,
>                           "Channel does not support file descriptor
>                           passing");
>          return -1;
> diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
> index 45c13f1..a39abd5 100644
> --- a/migration/qemu-file-channel.c
> +++ b/migration/qemu-file-channel.c
> @@ -105,8 +105,7 @@ static int channel_shutdown(void *opaque,
>  {
>      QIOChannel *ioc = QIO_CHANNEL(opaque);
>  
> -    if (qio_channel_has_feature(ioc,
> -                                QIO_CHANNEL_FEATURE_SHUTDOWN)) {
> +    if (qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
>          QIOChannelShutdown mode;
>          if (rd && wr) {
>              mode = QIO_CHANNEL_SHUTDOWN_BOTH;
> diff --git a/qemu-char.c b/qemu-char.c
> index 8826419..b825331 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2787,8 +2787,7 @@ static int tcp_set_msgfds(CharDriverState *chr, int
> *fds, int num)
>      s->write_msgfds_num = 0;
>  
>      if (!s->connected ||
> -        !qio_channel_has_feature(s->ioc,
> -                                 QIO_CHANNEL_FEATURE_FD_PASS)) {
> +        !qio_channel_has_feature(s->ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
>          return -1;
>      }
>  
> --
> 1.7.1
> 
>