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nhormandavem330
nhorman
authored and
davem330
committed
forcedeth: Do a dma_mapping_error check after skb_frag_dma_map
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] [<c045573c>] warn_slowpath_common+0x6c/0xa0 kernel: [17539.341012] [<c0701953>] ? check_unmap+0x493/0x960 kernel: [17539.341012] [<c0701953>] ? check_unmap+0x493/0x960 kernel: [17539.341012] [<c04557a3>] warn_slowpath_fmt+0x33/0x40 kernel: [17539.341012] [<c0701953>] check_unmap+0x493/0x960 kernel: [17539.341012] [<c049238f>] ? sched_clock_cpu+0xdf/0x150 kernel: [17539.341012] [<c0701e87>] debug_dma_unmap_page+0x67/0x70 kernel: [17539.341012] [<f7eae8f2>] 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 <nhorman@tuxdriver.com> CC: "David S. Miller" <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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‎drivers/net/ethernet/nvidia/forcedeth.c

Lines changed: 40 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -2200,6 +2200,7 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev)
22002200
struct ring_desc *start_tx;
22012201
struct ring_desc *prev_tx;
22022202
struct nv_skb_map *prev_tx_ctx;
2203+
struct nv_skb_map *tmp_tx_ctx = NULL, *start_tx_ctx = NULL;
22032204
unsigned long flags;
22042205

22052206
/* add fragments to entries count */
@@ -2261,12 +2262,31 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev)
22612262
do {
22622263
prev_tx = put_tx;
22632264
prev_tx_ctx = np->put_tx_ctx;
2265+
if (!start_tx_ctx)
2266+
start_tx_ctx = tmp_tx_ctx = np->put_tx_ctx;
2267+
22642268
bcnt = (frag_size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : frag_size;
22652269
np->put_tx_ctx->dma = skb_frag_dma_map(
22662270
&np->pci_dev->dev,
22672271
frag, offset,
22682272
bcnt,
22692273
DMA_TO_DEVICE);
2274+
if (dma_mapping_error(&np->pci_dev->dev, np->put_tx_ctx->dma)) {
2275+
2276+
/* Unwind the mapped fragments */
2277+
do {
2278+
nv_unmap_txskb(np, start_tx_ctx);
2279+
if (unlikely(tmp_tx_ctx++ == np->last_tx_ctx))
2280+
tmp_tx_ctx = np->first_tx_ctx;
2281+
} while (tmp_tx_ctx != np->put_tx_ctx);
2282+
kfree_skb(skb);
2283+
np->put_tx_ctx = start_tx_ctx;
2284+
u64_stats_update_begin(&np->swstats_tx_syncp);
2285+
np->stat_tx_dropped++;
2286+
u64_stats_update_end(&np->swstats_tx_syncp);
2287+
return NETDEV_TX_OK;
2288+
}
2289+
22702290
np->put_tx_ctx->dma_len = bcnt;
22712291
np->put_tx_ctx->dma_single = 0;
22722292
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,
23272347
struct ring_desc_ex *start_tx;
23282348
struct ring_desc_ex *prev_tx;
23292349
struct nv_skb_map *prev_tx_ctx;
2330-
struct nv_skb_map *start_tx_ctx;
2350+
struct nv_skb_map *start_tx_ctx = NULL;
2351+
struct nv_skb_map *tmp_tx_ctx = NULL;
23312352
unsigned long flags;
23322353

23332354
/* add fragments to entries count */
@@ -2392,11 +2413,29 @@ static netdev_tx_t nv_start_xmit_optimized(struct sk_buff *skb,
23922413
prev_tx = put_tx;
23932414
prev_tx_ctx = np->put_tx_ctx;
23942415
bcnt = (frag_size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : frag_size;
2416+
if (!start_tx_ctx)
2417+
start_tx_ctx = tmp_tx_ctx = np->put_tx_ctx;
23952418
np->put_tx_ctx->dma = skb_frag_dma_map(
23962419
&np->pci_dev->dev,
23972420
frag, offset,
23982421
bcnt,
23992422
DMA_TO_DEVICE);
2423+
2424+
if (dma_mapping_error(&np->pci_dev->dev, np->put_tx_ctx->dma)) {
2425+
2426+
/* Unwind the mapped fragments */
2427+
do {
2428+
nv_unmap_txskb(np, start_tx_ctx);
2429+
if (unlikely(tmp_tx_ctx++ == np->last_tx_ctx))
2430+
tmp_tx_ctx = np->first_tx_ctx;
2431+
} while (tmp_tx_ctx != np->put_tx_ctx);
2432+
kfree_skb(skb);
2433+
np->put_tx_ctx = start_tx_ctx;
2434+
u64_stats_update_begin(&np->swstats_tx_syncp);
2435+
np->stat_tx_dropped++;
2436+
u64_stats_update_end(&np->swstats_tx_syncp);
2437+
return NETDEV_TX_OK;
2438+
}
24002439
np->put_tx_ctx->dma_len = bcnt;
24012440
np->put_tx_ctx->dma_single = 0;
24022441
put_tx->bufhigh = cpu_to_le32(dma_high(np->put_tx_ctx->dma));

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