From 7fa2955ff70ce4532f144d26b8a087095f9c9ffc Mon Sep 17 00:00:00 2001 From: Mitsuhiro Kimura Date: Fri, 28 Nov 2014 10:04:15 +0900 Subject: [PATCH] sh_eth: Fix sleeping function called from invalid context This resolves the following bug which can be reproduced by building the kernel with CONFIG_DEBUG_ATOMIC_SLEEP=y and reading network statistics while the network interface is down. e.g.: ifconfig eth0 down cat /sys/class/net/eth0/statistics/tx_errors ---- [ 1238.161349] BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:952 [ 1238.188279] in_atomic(): 1, irqs_disabled(): 0, pid: 1388, name: cat [ 1238.207425] CPU: 0 PID: 1388 Comm: cat Not tainted 3.10.31-ltsi-00046-gefa0b46 #1087 [ 1238.230737] Backtrace: [ 1238.238123] [] (dump_backtrace+0x0/0x10c) from [] (show_stack+0x18/0x1c) [ 1238.263499] r6:000003b8 r5:c06160c0 r4:c0669e00 r3:00404000 [ 1238.280583] [] (show_stack+0x0/0x1c) from [] (dump_stack+0x20/0x28) [ 1238.304631] [] (dump_stack+0x0/0x28) from [] (__might_sleep+0xf8/0x118) [ 1238.329734] [] (__might_sleep+0x0/0x118) from [] (__pm_runtime_resume+0x38/0x90) [ 1238.357170] r7:d616f000 r6:c049c458 r5:00000004 r4:d6a17210 [ 1238.374251] [] (__pm_runtime_resume+0x0/0x90) from [] (sh_eth_get_stats+0x44/0x280) [ 1238.402468] r7:d616f000 r6:c049c458 r5:d5c21000 r4:d5c21000 [ 1238.419552] [] (sh_eth_get_stats+0x0/0x280) from [] (dev_get_stats+0x54/0x88) [ 1238.446204] r5:d5c21000 r4:d5ed7e08 [ 1238.456980] [] (dev_get_stats+0x0/0x88) from [] (netstat_show.isra.15+0x54/0x9c) [ 1238.484413] r6:d5c21000 r5:d5c21238 r4:00000028 r3:00000001 [ 1238.501495] [] (netstat_show.isra.15+0x0/0x9c) from [] (show_tx_errors+0x18/0x1c) [ 1238.529196] r7:d5f945d8 r6:d5f945c0 r5:c049716c r4:c0650e7c [ 1238.546279] [] (show_tx_errors+0x0/0x1c) from [] (dev_attr_show+0x24/0x50) [ 1238.572157] [] (dev_attr_show+0x0/0x50) from [] (sysfs_read_file+0xb0/0x140) [ 1238.598554] r5:c049716c r4:d5c21240 [ 1238.609326] [] (sysfs_read_file+0x0/0x140) from [] (vfs_read+0xb0/0x13c) [ 1238.634679] [] (vfs_read+0x0/0x13c) from [] (SyS_read+0x44/0x74) [ 1238.657944] r8:bef45bf0 r7:00000000 r6:d6ac0600 r5:00000000 r4:00000000 [ 1238.678172] [] (SyS_read+0x0/0x74) from [] (ret_fast_syscall+0x0/0x30) ---- Signed-off-by: Mitsuhiro Kimura Signed-off-by: Yoshihiro Kaneko Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/renesas/sh_eth.c | 64 +++++++++++++++------------ drivers/net/ethernet/renesas/sh_eth.h | 1 + 2 files changed, 36 insertions(+), 29 deletions(-) diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index f9e30b87ecd5..b5db6b3f939f 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -2036,6 +2036,8 @@ static int sh_eth_open(struct net_device *ndev) if (ret) goto out_free_irq; + mdp->is_opened = 1; + return ret; out_free_irq: @@ -2125,6 +2127,36 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev) return NETDEV_TX_OK; } +static struct net_device_stats *sh_eth_get_stats(struct net_device *ndev) +{ + struct sh_eth_private *mdp = netdev_priv(ndev); + + if (sh_eth_is_rz_fast_ether(mdp)) + return &ndev->stats; + + if (!mdp->is_opened) + return &ndev->stats; + + ndev->stats.tx_dropped += sh_eth_read(ndev, TROCR); + sh_eth_write(ndev, 0, TROCR); /* (write clear) */ + ndev->stats.collisions += sh_eth_read(ndev, CDCR); + sh_eth_write(ndev, 0, CDCR); /* (write clear) */ + ndev->stats.tx_carrier_errors += sh_eth_read(ndev, LCCR); + sh_eth_write(ndev, 0, LCCR); /* (write clear) */ + + if (sh_eth_is_gether(mdp)) { + ndev->stats.tx_carrier_errors += sh_eth_read(ndev, CERCR); + sh_eth_write(ndev, 0, CERCR); /* (write clear) */ + ndev->stats.tx_carrier_errors += sh_eth_read(ndev, CEECR); + sh_eth_write(ndev, 0, CEECR); /* (write clear) */ + } else { + ndev->stats.tx_carrier_errors += sh_eth_read(ndev, CNDCR); + sh_eth_write(ndev, 0, CNDCR); /* (write clear) */ + } + + return &ndev->stats; +} + /* device close function */ static int sh_eth_close(struct net_device *ndev) { @@ -2139,6 +2171,7 @@ static int sh_eth_close(struct net_device *ndev) sh_eth_write(ndev, 0, EDTRR); sh_eth_write(ndev, 0, EDRRR); + sh_eth_get_stats(ndev); /* PHY Disconnect */ if (mdp->phydev) { phy_stop(mdp->phydev); @@ -2157,36 +2190,9 @@ static int sh_eth_close(struct net_device *ndev) pm_runtime_put_sync(&mdp->pdev->dev); - return 0; -} - -static struct net_device_stats *sh_eth_get_stats(struct net_device *ndev) -{ - struct sh_eth_private *mdp = netdev_priv(ndev); - - if (sh_eth_is_rz_fast_ether(mdp)) - return &ndev->stats; - - pm_runtime_get_sync(&mdp->pdev->dev); - - ndev->stats.tx_dropped += sh_eth_read(ndev, TROCR); - sh_eth_write(ndev, 0, TROCR); /* (write clear) */ - ndev->stats.collisions += sh_eth_read(ndev, CDCR); - sh_eth_write(ndev, 0, CDCR); /* (write clear) */ - ndev->stats.tx_carrier_errors += sh_eth_read(ndev, LCCR); - sh_eth_write(ndev, 0, LCCR); /* (write clear) */ - if (sh_eth_is_gether(mdp)) { - ndev->stats.tx_carrier_errors += sh_eth_read(ndev, CERCR); - sh_eth_write(ndev, 0, CERCR); /* (write clear) */ - ndev->stats.tx_carrier_errors += sh_eth_read(ndev, CEECR); - sh_eth_write(ndev, 0, CEECR); /* (write clear) */ - } else { - ndev->stats.tx_carrier_errors += sh_eth_read(ndev, CNDCR); - sh_eth_write(ndev, 0, CNDCR); /* (write clear) */ - } - pm_runtime_put_sync(&mdp->pdev->dev); + mdp->is_opened = 0; - return &ndev->stats; + return 0; } /* ioctl to device function */ diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h index 9fa93321d512..22301bf9c21d 100644 --- a/drivers/net/ethernet/renesas/sh_eth.h +++ b/drivers/net/ethernet/renesas/sh_eth.h @@ -522,6 +522,7 @@ struct sh_eth_private { unsigned no_ether_link:1; unsigned ether_link_active_low:1; + unsigned is_opened:1; }; static inline void sh_eth_soft_swap(char *src, int len) -- 2.20.1