Skip to content
This repository has been archived by the owner on Nov 7, 2021. It is now read-only.

Commit

Permalink
sh_eth: Fix sleeping function called from invalid context
Browse files Browse the repository at this point in the history 
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] [<c0012e64>] (dump_backtrace+0x0/0x10c) from [<c0013000>] (show_stack+0x18/0x1c)
[ 1238.263499]  r6:000003b8 r5:c06160c0 r4:c0669e00 r3:00404000
[ 1238.280583] [<c0012fe8>] (show_stack+0x0/0x1c) from [<c04515a4>] (dump_stack+0x20/0x28)
[ 1238.304631] [<c0451584>] (dump_stack+0x0/0x28) from [<c004970c>] (__might_sleep+0xf8/0x118)
[ 1238.329734] [<c0049614>] (__might_sleep+0x0/0x118) from [<c02465ac>] (__pm_runtime_resume+0x38/0x90)
[ 1238.357170]  r7:d616f000 r6:c049c458 r5:00000004 r4:d6a17210
[ 1238.374251] [<c0246574>] (__pm_runtime_resume+0x0/0x90) from [<c029b1c4>] (sh_eth_get_stats+0x44/0x280)
[ 1238.402468]  r7:d616f000 r6:c049c458 r5:d5c21000 r4:d5c21000
[ 1238.419552] [<c029b180>] (sh_eth_get_stats+0x0/0x280) from [<c03ae39c>] (dev_get_stats+0x54/0x88)
[ 1238.446204]  r5:d5c21000 r4:d5ed7e08
[ 1238.456980] [<c03ae348>] (dev_get_stats+0x0/0x88) from [<c03c677c>] (netstat_show.isra.15+0x54/0x9c)
[ 1238.484413]  r6:d5c21000 r5:d5c21238 r4:00000028 r3:00000001
[ 1238.501495] [<c03c6728>] (netstat_show.isra.15+0x0/0x9c) from [<c03c69b8>] (show_tx_errors+0x18/0x1c)
[ 1238.529196]  r7:d5f945d8 r6:d5f945c0 r5:c049716c r4:c0650e7c
[ 1238.546279] [<c03c69a0>] (show_tx_errors+0x0/0x1c) from [<c023963c>] (dev_attr_show+0x24/0x50)
[ 1238.572157] [<c0239618>] (dev_attr_show+0x0/0x50) from [<c010c148>] (sysfs_read_file+0xb0/0x140)
[ 1238.598554]  r5:c049716c r4:d5c21240
[ 1238.609326] [<c010c098>] (sysfs_read_file+0x0/0x140) from [<c00b9ee4>] (vfs_read+0xb0/0x13c)
[ 1238.634679] [<c00b9e34>] (vfs_read+0x0/0x13c) from [<c00ba0ac>] (SyS_read+0x44/0x74)
[ 1238.657944]  r8:bef45bf0 r7:00000000 r6:d6ac0600 r5:00000000 r4:00000000
[ 1238.678172] [<c00ba068>] (SyS_read+0x0/0x74) from [<c000eec0>] (ret_fast_syscall+0x0/0x30)
----

Signed-off-by: Mitsuhiro Kimura <[email protected]>
Signed-off-by: Yoshihiro Kaneko <[email protected]>
Signed-off-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
  • Loading branch information
@mitsu-kimura @davem330
mitsu-kimura authored and davem330 committed Nov 30, 2014
1 parent 28603d1 commit 7fa2955
Show file tree
Hide file tree
Showing 2 changed files with 36 additions and 29 deletions.
64 changes: 35 additions & 29 deletions drivers/net/ethernet/renesas/sh_eth.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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:
Expand Down Expand Up @@ -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)
{
Expand All @@ -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);
Expand All @@ -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 */
Expand Down
1 change: 1 addition & 0 deletions drivers/net/ethernet/renesas/sh_eth.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down

0 comments on commit 7fa2955

Please sign in to comment.