Hi Dan, On Tue, 26 May 2020 at 17:55, Dan Carpenter <[email protected]> wrote: > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > master > head: 9cb1fd0efd195590b828b9b865421ad345a4a145 > commit: c80ed84e76886487703bf04b38ce10e92e2d6e26 net: dsa: tag_8021q: Fix > dsa_8021q_restore_pvid for an absent pvid > date: 6 months ago > config: x86_64-randconfig-m001-20200526 (attached as .config) > compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kbuild test robot <[email protected]> > Reported-by: Dan Carpenter <[email protected]> > > smatch warnings: > net/dsa/tag_8021q.c:109 dsa_8021q_restore_pvid() error: uninitialized symbol > 'pvid'. > > # > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c80ed84e76886487703bf04b38ce10e92e2d6e26 > git remote add linus > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git remote update linus > git checkout c80ed84e76886487703bf04b38ce10e92e2d6e26 > vim +/pvid +109 net/dsa/tag_8021q.c > > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 96 static int > dsa_8021q_restore_pvid(struct dsa_switch *ds, int port) > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 97 { > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 98 struct > bridge_vlan_info vinfo; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 99 struct net_device > *slave; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 100 u16 pvid; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 101 int err; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 102 > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 103 if > (!dsa_is_user_port(ds, port)) > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 104 return 0; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 105 > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 106 slave = > ds->ports[port].slave; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 107 > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 108 err = > br_vlan_get_pvid(slave, &pvid); > c80ed84e768864 Vladimir Oltean 2019-11-16 @109 if (!pvid || err < 0) > ^^^^^^^^^^^^^^^^ > I don't know why this warning is only showing up now in May 2020... > Anyway, we could solve the problem by checking for errors first: > > if (err < 0 || !pvid) { > > The UBSan tool can detect uninitialized values used at runtime so it > might generate a splat as well. Other than that, obviously it is > harmless. > > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 110 /* There is > no pvid on the bridge for this port, which is > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 111 * perfectly > valid. Nothing to restore, bye-bye! > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 112 */ > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 113 return 0; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 114 > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 115 err = > br_vlan_get_info(slave, pvid, &vinfo); > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 116 if (err < 0) { > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 117 > dev_err(ds->dev, "Couldn't determine PVID attributes\n"); > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 118 return err; > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 119 } > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 120 > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 121 return > dsa_port_vid_add(&ds->ports[port], pvid, vinfo.flags); > 5f33183b7fdfeb Vladimir Oltean 2019-08-30 122 } > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/[email protected]
For net-next I just sent a patch that removes this function altogether: https://patchwork.ozlabs.org/project/netdev/patch/[email protected]/ Do you think a patch for the net tree is still necessary, that reorders the checks? Will you send that patch or should I? Thanks, -Vladimir
