target/linux/layerscape/patches-5.4/809-jailhouse-0010-ivshmem-net-Switch-to-relative-descriptor-addresses.patch

   1 From dd462c6eb2ba6af01ae38644183216c4d5603d90 Mon Sep 17 00:00:00 2001
   2 From: Jan Kiszka <jan.kiszka@siemens.com>
   3 Date: Tue, 3 Jan 2017 08:50:01 +0100
   4 Subject: [PATCH] ivshmem-net: Switch to relative descriptor addresses
   5
   6 Make sure that we do not depend on identity-mapped shared memory
   7 regions.
   8
   9 This also fixes an off-by-one in the range check of ivshm_net_desc_data.
  10
  11 Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
  12 (cherry picked from commit fe9c9dd6373892591a7d6b165c3c43045eb349c1)
  13 ---
  14  drivers/net/ivshmem-net.c | 8 ++++----
  15  1 file changed, 4 insertions(+), 4 deletions(-)
  16
  17 --- a/drivers/net/ivshmem-net.c
  18 +++ b/drivers/net/ivshmem-net.c
  19 @@ -123,14 +123,14 @@ static void *ivshm_net_desc_data(struct
  20                                  struct vring_desc *desc,
  21                                  u32 *len)
  22  {
  23 -       u64 addr = READ_ONCE(desc->addr);
  24 +       u64 offs = READ_ONCE(desc->addr);
  25         u32 dlen = READ_ONCE(desc->len);
  26         void *data;
  27
  28 -       if (addr < in->shmaddr || desc->addr > in->shmaddr + in->shmlen)
  29 +       if (offs >= in->shmlen)
  30                 return NULL;
  31
  32 -       data = in->shm + (addr - in->shmaddr);
  33 +       data = in->shm + offs;
  34
  35         if (data < q->data || data >= q->end)
  36                 return NULL;
  37 @@ -317,7 +317,7 @@ static int ivshm_net_tx_frame(struct net
  38         buf = tx->data + head;
  39         skb_copy_and_csum_dev(skb, buf);
  40
  41 -       desc->addr = in->shmaddr + (buf - in->shm);
  42 +       desc->addr = buf - in->shm;
  43         desc->len = skb->len;
  44
  45         avail = tx->last_avail_idx++ & (vr->num - 1);