| Message ID | 20170920115813.63745-2-ubraun@linux.vnet.ibm.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | net/smc: updates 2017-09-20 | expand |
Hi Ursula, Dave, Hans, > -----Original Message----- > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma- > owner@vger.kernel.org] On Behalf Of Ursula Braun > Sent: Wednesday, September 20, 2017 6:58 AM > To: davem@davemloft.net > Cc: netdev@vger.kernel.org; linux-rdma@vger.kernel.org; linux- > s390@vger.kernel.org; jwi@linux.vnet.ibm.com; schwidefsky@de.ibm.com; > heiko.carstens@de.ibm.com; raspl@linux.vnet.ibm.com; > ubraun@linux.vnet.ibm.com > Subject: [PATCH net-next 01/10] net/smc: add missing dev_put > > From: Hans Wippel <hwippel@linux.vnet.ibm.com> > > In the infiniband part, SMC currently uses get_netdev which calls dev_hold on > the returned net device. However, the SMC code never calls dev_put on that net > device resulting in a wrong reference count. > > This patch adds a dev_put after the usage of the net device to fix the issue. > > Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com> > Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> > --- > net/smc/smc_ib.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index > 547e0e113b17..0b5852299158 100644 > --- a/net/smc/smc_ib.c > +++ b/net/smc/smc_ib.c > @@ -380,6 +380,7 @@ static int smc_ib_fill_gid_and_mac(struct smc_ib_device > *smcibdev, u8 ibport) > ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport); > if (ndev) { > memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN); > + dev_put(ndev); I am sorry for providing late comments. smc_ib_fill_gid_and_mac() is not coded correctly. Few fixes are needed. 1. ULP such as SMC should not open code/deference any function pointer like get_netdev() of the IB device. 2. Replace ib_query_gid(..., NULL) With ib_query_gid(..., gid_attr); Use gid_attr.ndev to get the MAC address. Do dev_put(gid_attr.ndev); Code should look like below, struct ib_gid_attr gid_attr; rc = ib_query_gid(..., &gid_attr); if (rc || !gid_addr.ndev) return -ENODEV; else memcpy(smcibdev->mac, ndev->dev_addr, ETH_ALEN); dev_put(gid_addr.ndev);
> -----Original Message----- > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma- > owner@vger.kernel.org] On Behalf Of Parav Pandit > Sent: Monday, October 02, 2017 3:36 PM > To: Ursula Braun <ubraun@linux.vnet.ibm.com>; davem@davemloft.net > Cc: netdev@vger.kernel.org; linux-rdma@vger.kernel.org; linux- > s390@vger.kernel.org; jwi@linux.vnet.ibm.com; schwidefsky@de.ibm.com; > heiko.carstens@de.ibm.com; raspl@linux.vnet.ibm.com > Subject: RE: [PATCH net-next 01/10] net/smc: add missing dev_put > > Hi Ursula, Dave, Hans, > > > -----Original Message----- > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma- > > owner@vger.kernel.org] On Behalf Of Ursula Braun > > Sent: Wednesday, September 20, 2017 6:58 AM > > To: davem@davemloft.net > > Cc: netdev@vger.kernel.org; linux-rdma@vger.kernel.org; linux- > > s390@vger.kernel.org; jwi@linux.vnet.ibm.com; schwidefsky@de.ibm.com; > > heiko.carstens@de.ibm.com; raspl@linux.vnet.ibm.com; > > ubraun@linux.vnet.ibm.com > > Subject: [PATCH net-next 01/10] net/smc: add missing dev_put > > > > From: Hans Wippel <hwippel@linux.vnet.ibm.com> > > > > In the infiniband part, SMC currently uses get_netdev which calls > > dev_hold on the returned net device. However, the SMC code never calls > > dev_put on that net device resulting in a wrong reference count. > > > > This patch adds a dev_put after the usage of the net device to fix the issue. > > > > Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com> > > Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> > > --- > > net/smc/smc_ib.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index > > 547e0e113b17..0b5852299158 100644 > > --- a/net/smc/smc_ib.c > > +++ b/net/smc/smc_ib.c > > @@ -380,6 +380,7 @@ static int smc_ib_fill_gid_and_mac(struct > > smc_ib_device *smcibdev, u8 ibport) > > ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport); > > if (ndev) { > > memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN); > > + dev_put(ndev); > > I am sorry for providing late comments. smc_ib_fill_gid_and_mac() is not coded > correctly. > Few fixes are needed. > 1. ULP such as SMC should not open code/deference any function pointer like > get_netdev() of the IB device. > 2. Replace ib_query_gid(..., NULL) > With > ib_query_gid(..., gid_attr); > > Use gid_attr.ndev to get the MAC address. > Do dev_put(gid_attr.ndev); > > Code should look like below, > > struct ib_gid_attr gid_attr; > > rc = ib_query_gid(..., &gid_attr); > if (rc || !gid_addr.ndev) > return -ENODEV; > else > memcpy(smcibdev->mac, ndev->dev_addr, ETH_ALEN); > dev_put(gid_addr.ndev); > -- Also, smc_link_determine_gid() doesn't do dev_put(gattr.ndev) in for loop. Please fix it as well.
On 10/02/2017 10:36 PM, Parav Pandit wrote: > Hi Ursula, Dave, Hans, > >> -----Original Message----- >> From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma- >> owner@vger.kernel.org] On Behalf Of Ursula Braun >> Sent: Wednesday, September 20, 2017 6:58 AM >> To: davem@davemloft.net >> Cc: netdev@vger.kernel.org; linux-rdma@vger.kernel.org; linux- >> s390@vger.kernel.org; jwi@linux.vnet.ibm.com; schwidefsky@de.ibm.com; >> heiko.carstens@de.ibm.com; raspl@linux.vnet.ibm.com; >> ubraun@linux.vnet.ibm.com >> Subject: [PATCH net-next 01/10] net/smc: add missing dev_put >> >> From: Hans Wippel <hwippel@linux.vnet.ibm.com> >> >> In the infiniband part, SMC currently uses get_netdev which calls dev_hold on >> the returned net device. However, the SMC code never calls dev_put on that net >> device resulting in a wrong reference count. >> >> This patch adds a dev_put after the usage of the net device to fix the issue. >> >> Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com> >> Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> >> --- >> net/smc/smc_ib.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index >> 547e0e113b17..0b5852299158 100644 >> --- a/net/smc/smc_ib.c >> +++ b/net/smc/smc_ib.c >> @@ -380,6 +380,7 @@ static int smc_ib_fill_gid_and_mac(struct smc_ib_device >> *smcibdev, u8 ibport) >> ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport); >> if (ndev) { >> memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN); >> + dev_put(ndev); > > I am sorry for providing late comments. smc_ib_fill_gid_and_mac() is not coded correctly. > Few fixes are needed. > 1. ULP such as SMC should not open code/deference any function pointer like get_netdev() of the IB device. > 2. Replace ib_query_gid(..., NULL) > With > ib_query_gid(..., gid_attr); > > Use gid_attr.ndev to get the MAC address. > Do dev_put(gid_attr.ndev); > > Code should look like below, > > struct ib_gid_attr gid_attr; > > rc = ib_query_gid(..., &gid_attr); > if (rc || !gid_addr.ndev) > return -ENODEV; > else > memcpy(smcibdev->mac, ndev->dev_addr, ETH_ALEN); > dev_put(gid_addr.ndev); > Thanks, Parav! Following your fix ideas I plan to change the function into this one: static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport) { struct ib_gid_attr gattr; int rc; rc = ib_query_gid(smcibdev->ibdev, ibport, 0, &smcibdev->gid[ibport - 1], &gattr); /* the SMC protocol requires specification of the roce MAC address; * if net_device cannot be determined, it can be derived from gid 0 */ if (rc) return rc; if (gattr.ndev) { memcpy(&smcibdev->mac, gattr.ndev->dev_addr, ETH_ALEN); dev_put(gattr.ndev); } else { memcpy(&smcibdev->mac[ibport - 1][0], &smcibdev->gid[ibport - 1].raw[8], 3); memcpy(&smcibdev->mac[ibport - 1][3], &smcibdev->gid[ibport - 1].raw[13], 3); smcibdev->mac[ibport - 1][0] &= ~0x02; } return 0; } If you agree, I will submit the corresponding patch including a Suggested-by: Parav Pandit <parav@mellanox.com> Regards, Ursula
Hi Ursula, > -----Original Message----- > From: Ursula Braun [mailto:ubraun@linux.vnet.ibm.com] > Sent: Thursday, October 05, 2017 2:54 AM > To: Parav Pandit <parav@mellanox.com> > Cc: davem@davemloft.net; netdev@vger.kernel.org; linux- > rdma@vger.kernel.org; linux-s390@vger.kernel.org; jwi@linux.vnet.ibm.com; > schwidefsky@de.ibm.com; heiko.carstens@de.ibm.com; > raspl@linux.vnet.ibm.com > Subject: Re: [PATCH net-next 01/10] net/smc: add missing dev_put > > > > On 10/02/2017 10:36 PM, Parav Pandit wrote: > > Hi Ursula, Dave, Hans, > > > >> -----Original Message----- > >> From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma- > >> owner@vger.kernel.org] On Behalf Of Ursula Braun > >> Sent: Wednesday, September 20, 2017 6:58 AM > >> To: davem@davemloft.net > >> Cc: netdev@vger.kernel.org; linux-rdma@vger.kernel.org; linux- > >> s390@vger.kernel.org; jwi@linux.vnet.ibm.com; schwidefsky@de.ibm.com; > >> heiko.carstens@de.ibm.com; raspl@linux.vnet.ibm.com; > >> ubraun@linux.vnet.ibm.com > >> Subject: [PATCH net-next 01/10] net/smc: add missing dev_put > >> > >> From: Hans Wippel <hwippel@linux.vnet.ibm.com> > >> > >> In the infiniband part, SMC currently uses get_netdev which calls > >> dev_hold on the returned net device. However, the SMC code never > >> calls dev_put on that net device resulting in a wrong reference count. > >> > >> This patch adds a dev_put after the usage of the net device to fix the issue. > >> > >> Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com> > >> Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> > >> --- > >> net/smc/smc_ib.c | 1 + > >> 1 file changed, 1 insertion(+) > >> > >> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index > >> 547e0e113b17..0b5852299158 100644 > >> --- a/net/smc/smc_ib.c > >> +++ b/net/smc/smc_ib.c > >> @@ -380,6 +380,7 @@ static int smc_ib_fill_gid_and_mac(struct > >> smc_ib_device *smcibdev, u8 ibport) > >> ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport); > >> if (ndev) { > >> memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN); > >> + dev_put(ndev); > > > > I am sorry for providing late comments. smc_ib_fill_gid_and_mac() is not > coded correctly. > > Few fixes are needed. > > 1. ULP such as SMC should not open code/deference any function pointer like > get_netdev() of the IB device. > > 2. Replace ib_query_gid(..., NULL) > > With > > ib_query_gid(..., gid_attr); > > > > Use gid_attr.ndev to get the MAC address. > > Do dev_put(gid_attr.ndev); > > > > Code should look like below, > > > > struct ib_gid_attr gid_attr; > > > > rc = ib_query_gid(..., &gid_attr); > > if (rc || !gid_addr.ndev) > > return -ENODEV; > > else > > memcpy(smcibdev->mac, ndev->dev_addr, ETH_ALEN); > > dev_put(gid_addr.ndev); > > > > Thanks, Parav! > Following your fix ideas I plan to change the function into this one: > > static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport) { > struct ib_gid_attr gattr; > int rc; > > rc = ib_query_gid(smcibdev->ibdev, ibport, 0, > &smcibdev->gid[ibport - 1], &gattr); > /* the SMC protocol requires specification of the roce MAC address; > * if net_device cannot be determined, it can be derived from gid 0 > */ > if (rc) > return rc; > > if (gattr.ndev) { > memcpy(&smcibdev->mac, gattr.ndev->dev_addr, ETH_ALEN); > dev_put(gattr.ndev); > } else { > memcpy(&smcibdev->mac[ibport - 1][0], > &smcibdev->gid[ibport - 1].raw[8], 3); > memcpy(&smcibdev->mac[ibport - 1][3], > &smcibdev->gid[ibport - 1].raw[13], 3); > smcibdev->mac[ibport - 1][0] &= ~0x02; This else part is not needed. You can fail the call as suggested above, inline below too. if (rc || !gid_addr.ndev) return -ENODEV; There must be valid netdev for RoCE gid. Rest code looks fine.
diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index 547e0e113b17..0b5852299158 100644 --- a/net/smc/smc_ib.c +++ b/net/smc/smc_ib.c @@ -380,6 +380,7 @@ static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport) ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport); if (ndev) { memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN); + dev_put(ndev); } else if (!rc) { memcpy(&smcibdev->mac[ibport - 1][0], &smcibdev->gid[ibport - 1].raw[8], 3);