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authorUrsula Braun <ubraun@linux.ibm.com>2020-07-08 18:05:13 +0300
committerDavid S. Miller <davem@davemloft.net>2020-07-08 22:35:15 +0300
commit92f3cb0e11dda530d1daa42d7a11af5a92ed89e4 (patch)
treee26722f5cddc21ef13e0985e9cc05b1bb077a1bc /net/smc/smc_pnet.c
parentb7eede757883a9892dcb7bf0280f4890fc74bcf6 (diff)
downloadlinux-92f3cb0e11dda530d1daa42d7a11af5a92ed89e4.tar.xz
net/smc: fix sleep bug in smc_pnet_find_roce_resource()
Tests showed this BUG: [572555.252867] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 [572555.252876] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 131031, name: smcapp [572555.252879] INFO: lockdep is turned off. [572555.252883] CPU: 1 PID: 131031 Comm: smcapp Tainted: G O 5.7.0-rc3uschi+ #356 [572555.252885] Hardware name: IBM 3906 M03 703 (LPAR) [572555.252887] Call Trace: [572555.252896] [<00000000ac364554>] show_stack+0x94/0xe8 [572555.252901] [<00000000aca1f400>] dump_stack+0xa0/0xe0 [572555.252906] [<00000000ac3c8c10>] ___might_sleep+0x260/0x280 [572555.252910] [<00000000acdc0c98>] __mutex_lock+0x48/0x940 [572555.252912] [<00000000acdc15c2>] mutex_lock_nested+0x32/0x40 [572555.252975] [<000003ff801762d0>] mlx5_lag_get_roce_netdev+0x30/0xc0 [mlx5_core] [572555.252996] [<000003ff801fb3aa>] mlx5_ib_get_netdev+0x3a/0xe0 [mlx5_ib] [572555.253007] [<000003ff80063848>] smc_pnet_find_roce_resource+0x1d8/0x310 [smc] [572555.253011] [<000003ff800602f0>] __smc_connect+0x1f0/0x3e0 [smc] [572555.253015] [<000003ff80060634>] smc_connect+0x154/0x190 [smc] [572555.253022] [<00000000acbed8d4>] __sys_connect+0x94/0xd0 [572555.253025] [<00000000acbef620>] __s390x_sys_socketcall+0x170/0x360 [572555.253028] [<00000000acdc6800>] system_call+0x298/0x2b8 [572555.253030] INFO: lockdep is turned off. Function smc_pnet_find_rdma_dev() might be called from smc_pnet_find_roce_resource(). It holds the smc_ib_devices list spinlock while calling infiniband op get_netdev(). At least for mlx5 the get_netdev operation wants mutex serialization, which conflicts with the smc_ib_devices spinlock. This patch switches the smc_ib_devices spinlock into a mutex to allow sleeping when calling get_netdev(). Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/smc/smc_pnet.c')
-rw-r--r--net/smc/smc_pnet.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index 014d91b9778e..d4aac31d39f5 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/list.h>
#include <linux/ctype.h>
+#include <linux/mutex.h>
#include <net/netlink.h>
#include <net/genetlink.h>
@@ -129,7 +130,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
return rc;
/* remove ib devices */
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
for (ibport = 0; ibport < SMC_MAX_PORTS; ibport++) {
if (ibdev->pnetid_by_user[ibport] &&
@@ -149,7 +150,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
}
}
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
/* remove smcd devices */
spin_lock(&smcd_dev_list.lock);
list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
@@ -240,14 +241,14 @@ static bool smc_pnet_apply_ib(struct smc_ib_device *ib_dev, u8 ib_port,
u8 pnet_null[SMC_MAX_PNETID_LEN] = {0};
bool applied = false;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
if (smc_pnet_match(ib_dev->pnetid[ib_port - 1], pnet_null)) {
memcpy(ib_dev->pnetid[ib_port - 1], pnet_name,
SMC_MAX_PNETID_LEN);
ib_dev->pnetid_by_user[ib_port - 1] = true;
applied = true;
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
return applied;
}
@@ -300,7 +301,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
{
struct smc_ib_device *ibdev;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
if (!strncmp(ibdev->ibdev->name, ib_name,
sizeof(ibdev->ibdev->name)) ||
@@ -311,7 +312,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
}
ibdev = NULL;
out:
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
return ibdev;
}
@@ -825,7 +826,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
int i;
ini->ib_dev = NULL;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
if (ibdev == known_dev)
continue;
@@ -844,7 +845,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
}
}
out:
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
}
/* find alternate roce device with same pnet_id and vlan_id */
@@ -863,7 +864,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
{
struct smc_ib_device *ibdev;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
struct net_device *ndev;
int i;
@@ -888,7 +889,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
}
}
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
}
/* Determine the corresponding IB device port based on the hardware PNETID.