This backtrace was recently reported on a 3.9 kernel: Actual results: from syslog /var/log/messsages: kernel: [17539.340285] ------------[ cut here ]------------ kernel: [17539.341012] WARNING: at lib/dma-debug.c:937 check_unmap+0x493/0x960() kernel: [17539.341012] Hardware name: MS-7125 kernel: [17539.341012] forcedeth 0000:00:0a.0: DMA-API: device driver failed to check map error[device address=0x0000000013c88000] [size=544 bytes] [mapped as page] kernel: [17539.341012] Modules linked in: fuse ebtable_nat ipt_MASQUERADE nf_conntrack_netbios_ns nf_conntrack_broadcast ip6table_nat nf_nat_ipv6 ip6table_mangle ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 iptable_nat nf_nat_ipv4 nf_nat iptable_mangle nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack bnep bluetooth rfkill ebtable_filter ebtables ip6table_filter ip6_tables snd_hda_codec_hdmi snd_cmipci snd_mpu401_uart snd_hda_intel snd_intel8x0 snd_opl3_lib snd_ac97_codec gameport snd_hda_codec snd_rawmidi ac97_bus snd_hwdep snd_seq snd_seq_device snd_pcm snd_page_alloc snd_timer snd k8temp soundcore serio_raw i2c_nforce2 forcedeth ata_generic pata_acpi nouveau video mxm_wmi wmi i2c_algo_bit drm_kms_helper ttm drm i2c_core sata_sil pata_amd sata_nv uinput kernel: [17539.341012] Pid: 17340, comm: sshd Not tainted 3.9.0-0.rc4.git0.1.fc19.i686.PAE #1 kernel: [17539.341012] Call Trace: kernel: [17539.341012] [] warn_slowpath_common+0x6c/0xa0 kernel: [17539.341012] [] ? check_unmap+0x493/0x960 kernel: [17539.341012] [] ? check_unmap+0x493/0x960 kernel: [17539.341012] [] warn_slowpath_fmt+0x33/0x40 kernel: [17539.341012] [] check_unmap+0x493/0x960 kernel: [17539.341012] [] ? sched_clock_cpu+0xdf/0x150 kernel: [17539.341012] [] debug_dma_unmap_page+0x67/0x70 kernel: [17539.341012] [] nv_unmap_txskb.isra.32+0x92/0x100 Its pretty plainly the result of an skb fragment getting unmapped without having its initial mapping operation checked for errors. This patch corrects that. Signed-off-by: Neil Horman CC: "David S. Miller" --- drivers/net/ethernet/nvidia/forcedeth.c | 41 ++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c index b62262c..5ae1247 100644 --- a/drivers/net/ethernet/nvidia/forcedeth.c +++ b/drivers/net/ethernet/nvidia/forcedeth.c @@ -2200,6 +2200,7 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev) struct ring_desc *start_tx; struct ring_desc *prev_tx; struct nv_skb_map *prev_tx_ctx; + struct nv_skb_map *tmp_tx_ctx = NULL, *start_tx_ctx = NULL; unsigned long flags; /* add fragments to entries count */ @@ -2261,12 +2262,31 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev) do { prev_tx = put_tx; prev_tx_ctx = np->put_tx_ctx; + if (!start_tx_ctx) + start_tx_ctx = tmp_tx_ctx = np->put_tx_ctx; + bcnt = (frag_size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : frag_size; np->put_tx_ctx->dma = skb_frag_dma_map( &np->pci_dev->dev, frag, offset, bcnt, DMA_TO_DEVICE); + if (dma_mapping_error(&np->pci_dev->dev, np->put_tx_ctx->dma)) { + + /* Unwind the mapped fragments */ + do { + nv_unmap_txskb(np, start_tx_ctx); + if (unlikely(tmp_tx_ctx++ == np->last_tx_ctx)) + tmp_tx_ctx = np->first_tx_ctx; + } while (tmp_tx_ctx != np->put_tx_ctx); + kfree_skb(skb); + np->put_tx_ctx = start_tx_ctx; + u64_stats_update_begin(&np->swstats_tx_syncp); + np->stat_tx_dropped++; + u64_stats_update_end(&np->swstats_tx_syncp); + return NETDEV_TX_OK; + } + np->put_tx_ctx->dma_len = bcnt; np->put_tx_ctx->dma_single = 0; put_tx->buf = cpu_to_le32(np->put_tx_ctx->dma); @@ -2327,7 +2347,8 @@ static netdev_tx_t nv_start_xmit_optimized(struct sk_buff *skb, struct ring_desc_ex *start_tx; struct ring_desc_ex *prev_tx; struct nv_skb_map *prev_tx_ctx; - struct nv_skb_map *start_tx_ctx; + struct nv_skb_map *start_tx_ctx = NULL; + struct nv_skb_map *tmp_tx_ctx = NULL; unsigned long flags; /* add fragments to entries count */ @@ -2392,11 +2413,29 @@ static netdev_tx_t nv_start_xmit_optimized(struct sk_buff *skb, prev_tx = put_tx; prev_tx_ctx = np->put_tx_ctx; bcnt = (frag_size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : frag_size; + if (!start_tx_ctx) + start_tx_ctx = tmp_tx_ctx = np->put_tx_ctx; np->put_tx_ctx->dma = skb_frag_dma_map( &np->pci_dev->dev, frag, offset, bcnt, DMA_TO_DEVICE); + + if (dma_mapping_error(&np->pci_dev->dev, np->put_tx_ctx->dma)) { + + /* Unwind the mapped fragments */ + do { + nv_unmap_txskb(np, start_tx_ctx); + if (unlikely(tmp_tx_ctx++ == np->last_tx_ctx)) + tmp_tx_ctx = np->first_tx_ctx; + } while (tmp_tx_ctx != np->put_tx_ctx); + kfree_skb(skb); + np->put_tx_ctx = start_tx_ctx; + u64_stats_update_begin(&np->swstats_tx_syncp); + np->stat_tx_dropped++; + u64_stats_update_end(&np->swstats_tx_syncp); + return NETDEV_TX_OK; + } np->put_tx_ctx->dma_len = bcnt; np->put_tx_ctx->dma_single = 0; put_tx->bufhigh = cpu_to_le32(dma_high(np->put_tx_ctx->dma)); -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html