On 10/02/2017 10:36 PM, Parav Pandit wrote: > Hi Ursula, Dave, Hans, > >> -----Original Message----- >> From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Ursula Braun >> Sent: Wednesday, September 20, 2017 6:58 AM >> To: davem@xxxxxxxxxxxxx >> Cc: netdev@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; linux- >> s390@xxxxxxxxxxxxxxx; jwi@xxxxxxxxxxxxxxxxxx; schwidefsky@xxxxxxxxxx; >> heiko.carstens@xxxxxxxxxx; raspl@xxxxxxxxxxxxxxxxxx; >> ubraun@xxxxxxxxxxxxxxxxxx >> Subject: [PATCH net-next 01/10] net/smc: add missing dev_put >> >> From: Hans Wippel <hwippel@xxxxxxxxxxxxxxxxxx> >> >> 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@xxxxxxxxxxxxxxxxxx> >> Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx> >> --- >> 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@xxxxxxxxxxxx> Regards, Ursula -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
