From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: [PATCH] libxl_qmp: Handle unexpected end-of-socket Date: Thu, 19 Jan 2012 15:35:22 +0000 Message-ID: <1326987322-28007-1-git-send-email-anthony.perard@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Xen Devel Cc: Anthony PERARD , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org When read() return 0, the current code just tries again. But this leads to an infinite loop if QEMU died too soon. Also, retry select if a signal was caught. Signed-off-by: Anthony PERARD --- tools/libxl/libxl_qmp.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/tools/libxl/libxl_qmp.c b/tools/libxl/libxl_qmp.c index 1777e44..d3b1d53 100644 --- a/tools/libxl/libxl_qmp.c +++ b/tools/libxl/libxl_qmp.c @@ -385,18 +385,22 @@ static int qmp_next(libxl__gc *gc, libxl__qmp_handler *qmp) FD_ZERO(&rfds); FD_SET(qmp->qmp_fd, &rfds); +do_select_again: ret = select(qmp->qmp_fd + 1, &rfds, NULL, NULL, &timeout); if (ret == 0) { LIBXL__LOG(qmp->ctx, LIBXL__LOG_ERROR, "timeout"); return -1; } else if (ret < 0) { + if (errno == EINTR) + goto do_select_again; LIBXL__LOG_ERRNO(qmp->ctx, LIBXL__LOG_ERROR, "Select error"); return -1; } rd = read(qmp->qmp_fd, qmp->buffer, QMP_RECEIVE_BUFFER_SIZE); if (rd == 0) { - continue; + LIBXL__LOG(qmp->ctx, LIBXL__LOG_ERROR, "Unexpected end of socket"); + return -1; } else if (rd < 0) { LIBXL__LOG_ERRNO(qmp->ctx, LIBXL__LOG_ERROR, "Socket read error"); return rd; -- tg: (6674c38..) fix/qmp-end-of-socket (depends on: master)