From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49775) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1zw6-0004dj-4U for qemu-devel@nongnu.org; Tue, 01 Jul 2014 11:25:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X1zvy-0007VX-Bh for qemu-devel@nongnu.org; Tue, 01 Jul 2014 11:25:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64243) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1zvy-0007VM-1s for qemu-devel@nongnu.org; Tue, 01 Jul 2014 11:25:26 -0400 From: Stefan Hajnoczi Date: Tue, 1 Jul 2014 17:25:07 +0200 Message-Id: <1404228309-21122-3-git-send-email-stefanha@redhat.com> In-Reply-To: <1404228309-21122-1-git-send-email-stefanha@redhat.com> References: <1404228309-21122-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PATCH v2 2/4] dataplane: do not free VirtQueueElement in vring_push() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Paolo Bonzini , ming.lei@canonical.com, Fam Zheng , Stefan Hajnoczi VirtQueueElement is allocated in vring_pop() so it seems to make sense that vring_push() should free it. Alas, virtio-blk frees VirtQueueElement itself in virtio_blk_free_request(). This patch solves a double-free assertion in glib's g_slice_free(). Rename vring_free_element() to vring_unmap_element() since it no longer frees the VirtQueueElement. Signed-off-by: Stefan Hajnoczi --- hw/virtio/dataplane/vring.c | 9 ++++----- include/hw/virtio/dataplane/vring.h | 1 - 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c index 665a1ff..5d17d39 100644 --- a/hw/virtio/dataplane/vring.c +++ b/hw/virtio/dataplane/vring.c @@ -272,7 +272,7 @@ static int get_indirect(Vring *vring, VirtQueueElement *elem, return 0; } -void vring_free_element(VirtQueueElement *elem) +static void vring_unmap_element(VirtQueueElement *elem) { int i; @@ -287,8 +287,6 @@ void vring_free_element(VirtQueueElement *elem) for (i = 0; i < elem->in_num; i++) { vring_unmap(elem->in_sg[i].iov_base, true); } - - g_slice_free(VirtQueueElement, elem); } /* This looks in the virtqueue and for the first available buffer, and converts @@ -402,7 +400,8 @@ out: vring->broken = true; } if (elem) { - vring_free_element(elem); + vring_unmap_element(elem); + g_slice_free(VirtQueueElement, elem); } *p_elem = NULL; return ret; @@ -418,7 +417,7 @@ void vring_push(Vring *vring, VirtQueueElement *elem, int len) unsigned int head = elem->index; uint16_t new; - vring_free_element(elem); + vring_unmap_element(elem); /* Don't touch vring if a fatal error occurred */ if (vring->broken) { diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h index 63e7bf4..b23edd2 100644 --- a/include/hw/virtio/dataplane/vring.h +++ b/include/hw/virtio/dataplane/vring.h @@ -55,6 +55,5 @@ bool vring_enable_notification(VirtIODevice *vdev, Vring *vring); bool vring_should_notify(VirtIODevice *vdev, Vring *vring); int vring_pop(VirtIODevice *vdev, Vring *vring, VirtQueueElement **elem); void vring_push(Vring *vring, VirtQueueElement *elem, int len); -void vring_free_element(VirtQueueElement *elem); #endif /* VRING_H */ -- 1.9.3