From mboxrd@z Thu Jan 1 00:00:00 1970 From: Max Gurtovoy Subject: Re: [PATCH] IB/core: Fix bit curruption in ib_device_cap_flags structure Date: Thu, 2 Jun 2016 19:41:10 +0300 Message-ID: <575061A6.1060302@mellanox.com> References: <1464859685-18666-1-git-send-email-maxg@mellanox.com> <20160602162426.GC26699@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160602162426.GC26699@kroah.com> Sender: stable-owner@vger.kernel.org To: Greg KH Cc: matanb@mellanox.com, leon@leon.nu, sagi@grimberg.me, linux-rdma@vger.kernel.org, stable@vger.kernel.org, robert@leblancnet.us List-Id: linux-rdma@vger.kernel.org On 6/2/2016 7:24 PM, Greg KH wrote: > On Thu, Jun 02, 2016 at 12:28:05PM +0300, Max Gurtovoy wrote: >> ib_device_cap_flags 64-bit expansion caused caps overlapping >> and made consumers read wrong device capabilities. For example >> IB_DEVICE_SG_GAPS_REG was falsely read by the iser driver causing >> it to use a non-existing capability. This happened because signed >> int becomes sign extended when converted it to u64. Fix this by >> casting IB_DEVICE_ON_DEMAND_PAGING enumeration to ULL. >> >> Fixes: fb532d6a79b9 ('IB/{core, ulp} Support above 32 possible device capability flags') >> Reported-by: Robert LeBlanc >> Cc: Stable #[v4.6+] >> Acked-by: Sagi Grimberg >> Signed-off-by: Max Gurtovoy >> Signed-off-by: Matan Barak >> --- >> include/rdma/ib_verbs.h | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h >> index 432bed5..c97357b 100644 >> --- a/include/rdma/ib_verbs.h >> +++ b/include/rdma/ib_verbs.h >> @@ -217,7 +217,7 @@ enum ib_device_cap_flags { >> IB_DEVICE_CROSS_CHANNEL = (1 << 27), >> IB_DEVICE_MANAGED_FLOW_STEERING = (1 << 29), >> IB_DEVICE_SIGNATURE_HANDOVER = (1 << 30), >> - IB_DEVICE_ON_DEMAND_PAGING = (1 << 31), >> + IB_DEVICE_ON_DEMAND_PAGING = (1ULL << 31), >> IB_DEVICE_SG_GAPS_REG = (1ULL << 32), >> IB_DEVICE_VIRTUAL_FUNCTION = ((u64)1 << 33), >> IB_DEVICE_RAW_SCATTER_FCS = ((u64)1 << 34), > > Why not just use the BIT() and BIT_ULL() macros instead of "open coding" > these? Good idea. do you think it will be a good idea to set all the elements in this ib_device_cap_flags enum to BIT_ULL() in this patch ? to have 1 style instead of many ? > > thanks, > > greg k-h >