From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56418) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gWlf9-0004Io-Ld for qemu-devel@nongnu.org; Tue, 11 Dec 2018 12:17:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gWlf3-0000hz-Rc for qemu-devel@nongnu.org; Tue, 11 Dec 2018 12:17:39 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:34988) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gWlf1-0000ff-St for qemu-devel@nongnu.org; Tue, 11 Dec 2018 12:17:33 -0500 Date: Tue, 11 Dec 2018 19:17:08 +0200 From: Yuval Shaia Message-ID: <20181211171707.GC2923@lap1> References: <20181211132642.3027-1-ppandit@redhat.com> <20181211132642.3027-6-ppandit@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181211132642.3027-6-ppandit@redhat.com> Subject: Re: [Qemu-devel] [PATCH 5/5] pvrdma: check return value from pvrdma_idx_ring_has_ routines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: P J P Cc: Qemu Developers , Marcel Apfelbaum , Saar Amar , Li Qiang , Prasad J Pandit , yuval.shaia@oracle.com On Tue, Dec 11, 2018 at 06:56:42PM +0530, P J P wrote: > From: Prasad J Pandit > > pvrdma_idx_ring_has_[data/space] routines also return invalid > index PVRDMA_INVALID_IDX[=-1], if ring has no data/space. Check > return value from these routines to avoid plausible infinite loops. > > Reported-by: Li Qiang > Signed-off-by: Prasad J Pandit > --- > hw/rdma/vmw/pvrdma_dev_ring.c | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c b/hw/rdma/vmw/pvrdma_dev_ring.c > index 01247fc041..61b6a0a869 100644 > --- a/hw/rdma/vmw/pvrdma_dev_ring.c > +++ b/hw/rdma/vmw/pvrdma_dev_ring.c > @@ -73,6 +73,7 @@ out: > > void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) > { > + int e; > unsigned int idx = 0, offset; > > /* > @@ -80,7 +81,8 @@ void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) > ring->ring_state->cons_head); > */ > > - if (!pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx)) { > + e = pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx); > + if (e <= 0) { > pr_dbg("No more data in ring\n"); > return NULL; > } > @@ -105,20 +107,24 @@ void pvrdma_ring_read_inc(PvrdmaRing *ring) > > void *pvrdma_ring_next_elem_write(PvrdmaRing *ring) > { > - unsigned int idx, offset, tail; > + int idx; > + unsigned int offset, tail; > > /* > pr_dbg("%s: t=%d, h=%d\n", ring->name, ring->ring_state->prod_tail, > ring->ring_state->cons_head); > */ > - > - if (!pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail)) { > + idx = pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail); > + if (idx <= 0) { > pr_dbg("CQ is full\n"); > return NULL; > } > > idx = pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems); > - /* TODO: tail == idx */ > + if (idx < 0 || tail == idx) { > + pr_dbg("invalid idx\n"); > + return NULL; > + } Thanks Prasad, Two cosmetic suggestions though: (1) In pvrdma_ring_next_elem_read, can you stick to your convention and replace 'e' with 'idx'? (2) Can you delete all leftover comments? In any case: Reviewed-by: Yuval Shaia > > offset = idx * ring->elem_sz; > return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); > -- > 2.19.2 >