Messages in this thread |  | | Date | Sat, 15 May 2021 19:56:47 +0300 | From | Dan Carpenter <> | Subject | Re: drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3598 mlxsw_sp_nexthop_group_refresh() warn: missing error code 'err' |
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On Sat, May 15, 2021 at 07:53:43PM +0300, Dan Carpenter wrote: > On Sat, May 15, 2021 at 06:48:40PM +0300, Ido Schimmel wrote: > > On Fri, May 14, 2021 at 05:35:00PM +0300, Dan Carpenter wrote: > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > > head: 315d99318179b9cd5077ccc9f7f26a164c9fa998 > > > commit: e3ddfb45bacdc623eedea7f7bf9e7879257471d6 mlxsw: spectrum_router: Allow returning errors from mlxsw_sp_nexthop_group_refresh() > > > config: x86_64-randconfig-m031-20210514 (attached as .config) > > > compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 > > > > > > If you fix the issue, kindly add following tag as appropriate > > > Reported-by: kernel test robot <lkp@intel.com> > > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > > > smatch warnings: > > > drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3598 mlxsw_sp_nexthop_group_refresh() warn: missing error code 'err' > > > > > > vim +/err +3598 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c > > > > > > e3ddfb45bacdc6 Ido Schimmel 2020-11-17 3555 static int > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3556 mlxsw_sp_nexthop_group_refresh(struct mlxsw_sp *mlxsw_sp, > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3557 struct mlxsw_sp_nexthop_group *nh_grp) > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3558 { > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3559 struct mlxsw_sp_nexthop_group_info *nhgi = nh_grp->nhgi; > > > eb789980d0aa6c Ido Schimmel 2017-10-22 3560 u16 ecmp_size, old_ecmp_size; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3561 struct mlxsw_sp_nexthop *nh; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3562 bool offload_change = false; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3563 u32 adj_index; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3564 bool old_adj_index_valid; > > > e3ddfb45bacdc6 Ido Schimmel 2020-11-17 3565 int i, err2, err = 0; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3566 u32 old_adj_index; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3567 > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3568 if (!nhgi->gateway) { > > > b3e8d1ebad2d04 Ido Schimmel 2017-02-08 3569 mlxsw_sp_nexthop_fib_entries_update(mlxsw_sp, nh_grp); > > > e3ddfb45bacdc6 Ido Schimmel 2020-11-17 3570 return 0; > > > b3e8d1ebad2d04 Ido Schimmel 2017-02-08 3571 } > > > b3e8d1ebad2d04 Ido Schimmel 2017-02-08 3572 > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3573 for (i = 0; i < nhgi->count; i++) { > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3574 nh = &nhgi->nexthops[i]; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3575 > > > 56b8a9ed276bc1 Petr Machata 2017-07-31 3576 if (nh->should_offload != nh->offloaded) { > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3577 offload_change = true; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3578 if (nh->should_offload) > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3579 nh->update = 1; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3580 } > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3581 } > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3582 if (!offload_change) { > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3583 /* Nothing was added or removed, so no need to reallocate. Just > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3584 * update MAC on existing adjacency indexes. > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3585 */ > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3586 err = mlxsw_sp_nexthop_group_update(mlxsw_sp, nhgi, false); > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3587 if (err) { > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3588 dev_warn(mlxsw_sp->bus_info->dev, "Failed to update neigh MAC in adjacency table.\n"); > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3589 goto set_trap; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3590 } > > > e3ddfb45bacdc6 Ido Schimmel 2020-11-17 3591 return 0; > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3592 } > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3593 mlxsw_sp_nexthop_group_normalize(nhgi); > > > 7f7a417e6a11d7 Ido Schimmel 2020-11-13 3594 if (!nhgi->sum_norm_weight) > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3595 /* No neigh of this group is connected so we just set > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3596 * the trap and let everthing flow through kernel. > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 3597 */ > > > a7ff87acd995e3 Jiri Pirko 2016-07-05 @3598 goto set_trap; > > > > > > The comments sort of imply that this is a success path so no error > > > code necessary. It's sort of hard to be positive though... > > > > Thanks for the report, Dan. This is indeed a success path. How do you > > suggest to handle it in order to avoid the warning on future smatch > > invocations? I regularly run smatch before submitting patches and I > > would like to keep it error/warning free. > > > > You could move setting the error to within 4 lines of the goto: > > err = 0; > goto set_trap; > > This check basically assumes that if you have a cleanup block after > a return 0; then it should return a negative error code. It finds > quite a few bugs and I'm generally happy with it. But like this is > open source and all so I'm also always open to different ideas if you > have a way to improve the check.
Actually, duh, I could make it a rule that if there is a comment like this before the goto then it's probably fine.
This is quite tricky to implement in Smatch because Smatch works on the preprocessed code so I can't promise that I will implement that change right away.
regards, dan carpenter
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