From: Aneesh Kumar K.V Date: Wed, 17 Aug 2011 16:56:04 +0000 (+0000) Subject: net/9p: Fix kernel crash with msize 512K X-Git-Tag: v3.0.5~145 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8926487ad88b00a9b6677f866df787dea7b3471b;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git net/9p: Fix kernel crash with msize 512K commit b49d8b5d7007a673796f3f99688b46931293873e upstream. With msize equal to 512K (PAGE_SIZE * VIRTQUEUE_NUM), we hit multiple crashes. This patch fix those. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Eric Van Hensbergen Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 175b513..e317583 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -263,7 +263,6 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req) { int in, out, inp, outp; struct virtio_chan *chan = client->trans; - char *rdata = (char *)req->rc+sizeof(struct p9_fcall); unsigned long flags; size_t pdata_off = 0; struct trans_rpage_info *rpinfo = NULL; @@ -346,7 +345,8 @@ req_retry_pinned: * Arrange in such a way that server places header in the * alloced memory and payload onto the user buffer. */ - inp = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, rdata, 11); + inp = pack_sg_list(chan->sg, out, + VIRTQUEUE_NUM, req->rc->sdata, 11); /* * Running executables in the filesystem may result in * a read request with kernel buffer as opposed to user buffer. @@ -366,8 +366,8 @@ req_retry_pinned: } in += inp; } else { - in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, rdata, - req->rc->capacity); + in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, + req->rc->sdata, req->rc->capacity); } err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc); @@ -592,7 +592,14 @@ static struct p9_trans_module p9_virtio_trans = { .close = p9_virtio_close, .request = p9_virtio_request, .cancel = p9_virtio_cancel, - .maxsize = PAGE_SIZE*VIRTQUEUE_NUM, + + /* + * We leave one entry for input and one entry for response + * headers. We also skip one more entry to accomodate, address + * that are not at page boundary, that can result in an extra + * page in zero copy. + */ + .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3), .pref = P9_TRANS_PREF_PAYLOAD_SEP, .def = 0, .owner = THIS_MODULE,