lkml.org 
[lkml]   [2019]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.19 003/170] ibmveth: fix DMA unmap error in ibmveth_xmit_start error path
    Date
    4.19-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>

    [ Upstream commit 756af9c642329d54f048bac2a62f829b391f6944 ]

    Commit 33a48ab105a7 ("ibmveth: Fix DMA unmap error") fixed an issue in the
    normal code path of ibmveth_xmit_start() that was originally introduced by
    Commit 6e8ab30ec677 ("ibmveth: Add scatter-gather support"). This original
    fix missed the error path where dma_unmap_page is wrongly called on the
    header portion in descs[0] which was mapped with dma_map_single. As a
    result a failure to DMA map any of the frags results in a dmesg warning
    when CONFIG_DMA_API_DEBUG is enabled.

    ------------[ cut here ]------------
    DMA-API: ibmveth 30000002: device driver frees DMA memory with wrong function
    [device address=0x000000000a430000] [size=172 bytes] [mapped as page] [unmapped as single]
    WARNING: CPU: 1 PID: 8426 at kernel/dma/debug.c:1085 check_unmap+0x4fc/0xe10
    ...
    <snip>
    ...
    DMA-API: Mapped at:
    ibmveth_start_xmit+0x30c/0xb60
    dev_hard_start_xmit+0x100/0x450
    sch_direct_xmit+0x224/0x490
    __qdisc_run+0x20c/0x980
    __dev_queue_xmit+0x1bc/0xf20

    This fixes the API misuse by unampping descs[0] with dma_unmap_single.

    Fixes: 6e8ab30ec677 ("ibmveth: Add scatter-gather support")
    Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/net/ethernet/ibm/ibmveth.c | 6 +++++-
    1 file changed, 5 insertions(+), 1 deletion(-)

    --- a/drivers/net/ethernet/ibm/ibmveth.c
    +++ b/drivers/net/ethernet/ibm/ibmveth.c
    @@ -1172,11 +1172,15 @@ out:

    map_failed_frags:
    last = i+1;
    - for (i = 0; i < last; i++)
    + for (i = 1; i < last; i++)
    dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address,
    descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK,
    DMA_TO_DEVICE);

    + dma_unmap_single(&adapter->vdev->dev,
    + descs[0].fields.address,
    + descs[0].fields.flags_len & IBMVETH_BUF_LEN_MASK,
    + DMA_TO_DEVICE);
    map_failed:
    if (!firmware_has_feature(FW_FEATURE_CMO))
    netdev_err(netdev, "tx: unable to map xmit buffer\n");

    \
     
     \ /
      Last update: 2019-01-07 18:24    [W:3.553 / U:0.476 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site