| Message ID | alpine.DEB.2.00.1102111232290.2826@kaball-desktop |
|---|---|
| State | New |
| Headers | show |
Am 11.02.2011 13:38, schrieb Stefano Stabellini: > When disk is a cdrom and the drive is empty the "params" node in > xenstore might be missing completely: cope with it instead of > segfaulting. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > > diff --git a/hw/xen_disk.c b/hw/xen_disk.c > index 134ac33..e553c4c 100644 > --- a/hw/xen_disk.c > +++ b/hw/xen_disk.c > @@ -577,12 +577,13 @@ static int blk_init(struct XenDevice *xendev) > { > struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); > int index, qflags, have_barriers, info = 0; > - char *h; > + char *h = NULL; > > /* read xenstore entries */ > if (blkdev->params == NULL) { > blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params"); > - h = strchr(blkdev->params, ':'); > + if (blkdev->params != NULL) > + h = strchr(blkdev->params, ':'); The coding style requires braces here. > if (h != NULL) { > blkdev->fileproto = blkdev->params; > blkdev->filename = h+1; Let me add some more context: if (h != NULL) { blkdev->fileproto = blkdev->params; blkdev->filename = h+1; *h = 0; } else { blkdev->fileproto = "<unset>"; blkdev->filename = blkdev->params; } So in the NULL case we now have blkdev->filename = NULL. Doesn't this just move the crash a few lines downwards when bdrv_open() tries to use NULL as its filename? Kevin
diff --git a/hw/xen_disk.c b/hw/xen_disk.c index 134ac33..e553c4c 100644 --- a/hw/xen_disk.c +++ b/hw/xen_disk.c @@ -577,12 +577,13 @@ static int blk_init(struct XenDevice *xendev) { struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); int index, qflags, have_barriers, info = 0; - char *h; + char *h = NULL; /* read xenstore entries */ if (blkdev->params == NULL) { blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params"); - h = strchr(blkdev->params, ':'); + if (blkdev->params != NULL) + h = strchr(blkdev->params, ':'); if (h != NULL) { blkdev->fileproto = blkdev->params; blkdev->filename = h+1;
When disk is a cdrom and the drive is empty the "params" node in xenstore might be missing completely: cope with it instead of segfaulting. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>