From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============4707974245327220269==" MIME-Version: 1.0 From: Paul E. McKenney To: kbuild-all@lists.01.org Subject: Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression Date: Mon, 28 Jun 2021 08:53:29 -0700 Message-ID: <20210628155329.GF4397@paulmck-ThinkPad-P17-Gen-1> In-Reply-To: <87tullkkrs.fsf@toke.dk> List-Id: --===============4707974245327220269== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke H=C3=B8iland-J=C3=B8rgensen = wrote: > +Paul - any idea why unrcu_pointer() isn't working here? Hello, Toke! My distro version of sparse core-dumped before getting that far along. I cloned and built the latest version, and got only the following errors from kernel/bpf/devmap.c: ------------------------------------------------------------------------ CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CC kernel/bpf/devmap.o CHECK kernel/bpf/devmap.c kernel/bpf/devmap.c:561:29: warning: incorrect type in assignment (differen= t address spaces) kernel/bpf/devmap.c:561:29: expected struct bpf_dtab_netdev *dst kernel/bpf/devmap.c:561:29: got struct bpf_dtab_netdev [noderef] __rcu * kernel/bpf/devmap.c:657:29: warning: incorrect type in assignment (differen= t address spaces) kernel/bpf/devmap.c:657:29: expected struct bpf_dtab_netdev *dst kernel/bpf/devmap.c:657:29: got struct bpf_dtab_netdev [noderef] __rcu * ------------------------------------------------------------------------ Might the kbuild test robot need to update their sparse? Thanx, Paul > -Toke > = > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.gi= t master > > head: a196fa78a26571359740f701cf30d774eb8a72cb > > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 [15/30] xdp: Add prope= r __rcu annotations to redirect map entries > > config: ia64-allmodconfig (attached as .config) > > compiler: ia64-linux-gcc (GCC) 9.3.0 > > reproduce: > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/s= bin/make.cross -O ~/bin/make.cross > > chmod +x ~/bin/make.cross > > # apt-get install sparse > > # sparse version: v0.6.3-341-g8af24329-dirty > > # https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.= git/commit/?id=3D782347b6bcad07ddb574422e01e22c92e05928c8 > > git remote add bpf-next https://git.kernel.org/pub/scm/linux/ke= rnel/git/bpf/bpf-next.git > > git fetch --no-tags bpf-next master > > git checkout 782347b6bcad07ddb574422e01e22c92e05928c8 > > # save the attached .config to linux build tree > > COMPILER_INSTALL_PATH=3D$HOME/0day COMPILER=3Dgcc-9.3.0 make.cr= oss C=3D1 CF=3D'-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=3D1 ARCH=3Dia64 = > > > > If you fix the issue, kindly add following tag as appropriate > > Reported-by: kernel test robot > > > > > > sparse warnings: (new ones prefixed by >>) > > kernel/bpf/devmap.c:561:29: sparse: sparse: incorrect type in assign= ment (different address spaces) @@ expected struct bpf_dtab_netdev *dst= @@ got struct bpf_dtab_netdev [noderef] __rcu * @@ > > kernel/bpf/devmap.c:561:29: sparse: expected struct bpf_dtab_net= dev *dst > > kernel/bpf/devmap.c:561:29: sparse: got struct bpf_dtab_netdev [= noderef] __rcu * > > kernel/bpf/devmap.c:657:29: sparse: sparse: incorrect type in assign= ment (different address spaces) @@ expected struct bpf_dtab_netdev *dst= @@ got struct bpf_dtab_netdev [noderef] __rcu * @@ > > kernel/bpf/devmap.c:657:29: sparse: expected struct bpf_dtab_net= dev *dst > > kernel/bpf/devmap.c:657:29: sparse: got struct bpf_dtab_netdev [= noderef] __rcu * > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address spa= ce '__rcu' of expression > > > > vim +/__rcu +1030 kernel/bpf/devmap.c > > > > 990 = > > 991 static int dev_map_notification(struct notifier_block *notifier, > > 992 ulong event, void *ptr) > > 993 { > > 994 struct net_device *netdev =3D netdev_notifier_info_to_dev(ptr); > > 995 struct bpf_dtab *dtab; > > 996 int i, cpu; > > 997 = > > 998 switch (event) { > > 999 case NETDEV_REGISTER: > > 1000 if (!netdev->netdev_ops->ndo_xdp_xmit || netdev->xdp_bulkq) > > 1001 break; > > 1002 = > > 1003 /* will be freed in free_netdev() */ > > 1004 netdev->xdp_bulkq =3D alloc_percpu(struct xdp_dev_bulk_queue); > > 1005 if (!netdev->xdp_bulkq) > > 1006 return NOTIFY_BAD; > > 1007 = > > 1008 for_each_possible_cpu(cpu) > > 1009 per_cpu_ptr(netdev->xdp_bulkq, cpu)->dev =3D netdev; > > 1010 break; > > 1011 case NETDEV_UNREGISTER: > > 1012 /* This rcu_read_lock/unlock pair is needed because > > 1013 * dev_map_list is an RCU list AND to ensure a delete > > 1014 * operation does not free a netdev_map entry while we > > 1015 * are comparing it against the netdev being unregistered. > > 1016 */ > > 1017 rcu_read_lock(); > > 1018 list_for_each_entry_rcu(dtab, &dev_map_list, list) { > > 1019 if (dtab->map.map_type =3D=3D BPF_MAP_TYPE_DEVMAP_HASH) { > > 1020 dev_map_hash_remove_netdev(dtab, netdev); > > 1021 continue; > > 1022 } > > 1023 = > > 1024 for (i =3D 0; i < dtab->map.max_entries; i++) { > > 1025 struct bpf_dtab_netdev *dev, *odev; > > 1026 = > > 1027 dev =3D rcu_dereference(dtab->netdev_map[i]); > > 1028 if (!dev || netdev !=3D dev->dev) > > 1029 continue; > >> 1030 odev =3D unrcu_pointer(cmpxchg(&dtab->netdev_map[i], RCU_INIT= IALIZER(dev), NULL)); > > 1031 if (dev =3D=3D odev) > > 1032 call_rcu(&dev->rcu, > > 1033 __dev_map_entry_free); > > 1034 } > > 1035 } > > 1036 rcu_read_unlock(); > > 1037 break; > > 1038 default: > > 1039 break; > > 1040 } > > 1041 return NOTIFY_OK; > > 1042 } > > 1043 = > > > > --- > > 0-DAY CI Kernel Test Service, Intel Corporation > > https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org >=20 --===============4707974245327220269==--