RE: [PATCH] fec_main iMX6Q DMA-API: device driver tries to free DMA memory it has not allocated
From: fugang.duan@xxxxxxxxxxxxx
Date: Wed Sep 03 2014 - 02:37:09 EST
From: Anand Moon <moon.linux@xxxxxxxxx> Sent: Tuesday, September 02, 2014 7:40 PM
>To: David S. Miller; Duan Fugang-B38611; Russell King; Li Frank-B20596;
>Estevam Fabio-R49496; Uwe Kleine-König
>Cc: netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Anand Moon
>Subject: [PATCH] fec_main iMX6Q DMA-API: device driver tries to free DMA
>memory it has not allocated
>
>Changes fix below warning:
>
>[ 167.331417] ------------[ cut here ]------------ [ 167.331456] WARNING:
>CPU: 0 PID: 1887 at lib/dma-debug.c:1080 check_unmap+0x7e4/0xb90()
>[ 167.331469] fec 2188000.ethernet: DMA-API: device driver tries to free
>DMA memory it has not allocated [device address=0x0000000000000000]
>[size=54 bytes] [ 167.331477] Modules linked in: zram lz4_compress rfcomm
>bnep bluetooth arc4 rt2800usb rt2800lib rt2x00usb rt2x00lib mac80211
>cfg80211 crc_ccitt rfkill rtc_snvs
>[ 167.331560] CPU: 0 PID: 1887 Comm: sshd Tainted: G W 3.17.0-rc3-
>armv7-x1 #1
>[ 167.331592] [<c001990c>] (unwind_backtrace) from [<c00141bc>]
>(show_stack+0x20/0x24) [ 167.331618] [<c00141bc>] (show_stack) from
>[<c0a8601c>] (dump_stack+0x9c/0xbc) [ 167.331647] [<c0a8601c>]
>(dump_stack) from [<c005586c>] (warn_slowpath_common+0x80/0x9c)
>[ 167.331665] [<c005586c>] (warn_slowpath_common) from [<c00558c8>]
>(warn_slowpath_fmt+0x40/0x48) [ 167.331682] [<c00558c8>]
>(warn_slowpath_fmt) from [<c05c377c>] (check_unmap+0x7e4/0xb90)
>[ 167.331699] [<c05c377c>] (check_unmap) from [<c05c3b98>]
>(debug_dma_unmap_page+0x70/0x78) [ 167.331725] [<c05c3b98>]
>(debug_dma_unmap_page) from [<c07678f0>] (fec_enet_rx_napi+0x5dc/0x8bc)
>[ 167.331751] [<c07678f0>] (fec_enet_rx_napi) from [<c0919ce0>]
>(net_rx_action+0x170/0x36c) [ 167.331769] [<c0919ce0>] (net_rx_action)
>from [<c005acbc>] (__do_softirq+0x1a0/0x558) [ 167.331783] [<c005acbc>]
>(__do_softirq) from [<c005b3d0>] (irq_exit+0xd0/0x114) [ 167.331804]
>[<c005b3d0>] (irq_exit) from [<c001064c>] (handle_IRQ+0x54/0xa0)
>[ 167.331820] [<c001064c>] (handle_IRQ) from [<c0008868>]
>(gic_handle_irq+0x3c/0x6c) [ 167.331839] [<c0008868>] (gic_handle_irq)
>from [<c0a8ef84>] (__irq_svc+0x44/0x5c) [ 167.331849] Exception
>stack(0xe41fbc40 to 0xe41fbc88) [ 167.331862] bc40: c00abd3c c0a8e0f0
>00000000 00000000 a0000013 c1aa83c0 c1aa83c0 c1aa83c0 [ 167.331874] bc60:
>00000001 000005b4 00000002 e41fbc9c c117d6e0 e41fbc88 c00abadc c0a8e0f4
>[ 167.331883] bc80: 60000013 ffffffff [ 167.331899] [<c0a8ef84>]
>(__irq_svc) from [<c0a8e0f4>] (_raw_spin_unlock_irqrestore+0x44/0x6c)
>[ 167.331918] [<c0a8e0f4>] (_raw_spin_unlock_irqrestore) from [<c00d8464>]
>(mod_timer+0x13c/0x2c0) [ 167.331938] [<c00d8464>] (mod_timer) from
>[<c08ff824>] (sk_reset_timer+0x28/0x50) [ 167.331957] [<c08ff824>]
>(sk_reset_timer) from [<c0978008>] (tcp_rearm_rto+0xa0/0x104)
>[ 167.331973] [<c0978008>] (tcp_rearm_rto) from [<c097b574>]
>(tcp_event_new_data_sent+0xa0/0xa4)
>[ 167.331989] [<c097b574>] (tcp_event_new_data_sent) from [<c097d518>]
>(tcp_write_xmit+0x1cc/0xd2c) [ 167.332004] [<c097d518>] (tcp_write_xmit)
>from [<c097e450>] (tcp_push_one+0x44/0x50) [ 167.332018] [<c097e450>]
>(tcp_push_one) from [<c096f3b8>] (tcp_sendmsg+0xbf8/0xd68) [ 167.332039]
>[<c096f3b8>] (tcp_sendmsg) from [<c09a17fc>] (inet_sendmsg+0x15c/0x25c)
>[ 167.332064] [<c09a17fc>] (inet_sendmsg) from [<c08f9e74>]
>(sock_aio_write+0xf8/0x118) [ 167.332091] [<c08f9e74>] (sock_aio_write)
>from [<c01e9560>] (do_sync_write+0x90/0xb8) [ 167.332108] [<c01e9560>]
>(do_sync_write) from [<c01ea12c>] (vfs_write+0x158/0x1e0) [ 167.332123]
>[<c01ea12c>] (vfs_write) from [<c01ea7e4>] (SyS_write+0x54/0xb0)
>[ 167.332140] [<c01ea7e4>] (SyS_write) from [<c000fc20>]
>(ret_fast_syscall+0x0/0x48) [ 167.332150] ---[ end trace
>e95c276a4fb5c451 ]---
>
>Signed-off-by: Anand Moon <moon.linux@xxxxxxxxx>
>---
> drivers/net/ethernet/freescale/fec_main.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/net/ethernet/freescale/fec_main.c
>b/drivers/net/ethernet/freescale/fec_main.c
>index 89355a7..b1d9b79 100644
>--- a/drivers/net/ethernet/freescale/fec_main.c
>+++ b/drivers/net/ethernet/freescale/fec_main.c
>@@ -444,8 +444,9 @@ dma_mapping_error:
> bdp = fep->cur_tx;
> for (i = 0; i < frag; i++) {
> bdp = fec_enet_get_nextdesc(bdp, fep);
>- dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
>- bdp->cbd_datlen, DMA_TO_DEVICE);
>+ if (bdp->cbd_bufaddr > 0)
>+ dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
>+ bdp->cbd_datlen, DMA_TO_DEVICE);
> }
I don't think there need to check cbd_bufaddr ?
> return NETDEV_TX_OK;
> }
>@@ -1106,7 +1107,8 @@ fec_enet_tx(struct net_device *ndev)
>
> skb = fep->tx_skbuff[index];
> fep->tx_skbuff[index] = NULL;
>- if (!IS_TSO_HEADER(fep, bdp->cbd_bufaddr))
>+ if (!IS_TSO_HEADER(fep, bdp->cbd_bufaddr) &&
>+ bdp->cbd_bufaddr > 0)
> dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
> bdp->cbd_datlen, DMA_TO_DEVICE);
> bdp->cbd_bufaddr = 0;
>@@ -2111,8 +2113,11 @@ static void fec_enet_free_buffers(struct net_device
>*ndev)
> skb = fep->rx_skbuff[i];
> fep->rx_skbuff[i] = NULL;
> if (skb) {
>- dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
>- FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
>+ if (bdp->cbd_bufaddr > 0)
>+ dma_unmap_single(&fep->pdev->dev,
>+ bdp->cbd_bufaddr,
>+ FEC_ENET_RX_FRSIZE,
>+ DMA_FROM_DEVICE);
> dev_kfree_skb(skb);
> }
> bdp = fec_enet_get_nextdesc(bdp, fep);
>--
>1.9.1
Thanks,
Andy
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