[PATCH v2 net] sh_eth: Fix sleeping function called from invalid context
Simon Horman
horms+renesas at verge.net.au
Thu Nov 27 17:04:15 PST 2014
From: Mitsuhiro Kimura <mitsuhiro.kimura.kc at renesas.com>
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 <mitsuhiro.kimura.kc at renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929 at gmail.com>
Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
---
v2 [Simon Horman]
* Enhance changelog to describe how the problem may be reproduced.
* Use bitfield rather than boolean for is_opened field of
struct sh_eth_private. As suggested by Sergei Shtylyov.
---
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 60e9c2c..862a691 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2042,6 +2042,8 @@ static int sh_eth_open(struct net_device *ndev)
if (ret)
goto out_free_irq;
+ mdp->is_opened = 1;
+
return ret;
out_free_irq:
@@ -2131,6 +2133,36 @@ 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)
{
@@ -2145,6 +2177,7 @@ 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);
@@ -2163,36 +2196,9 @@ 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 b37c427..81fcab3 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)
--
2.1.3
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