* kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression @ 2022-05-22 12:30 kernel test robot 2022-05-23 10:30 ` Toke Høiland-Jørgensen 0 siblings, 1 reply; 9+ messages in thread From: kernel test robot @ 2022-05-22 12:30 UTC (permalink / raw) To: Toke Høiland-Jørgensen Cc: kbuild-all, linux-kernel, Daniel Borkmann tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: eaea45fc0e7b6ae439526b4a41d91230c8517336 commit: 782347b6bcad07ddb574422e01e22c92e05928c8 xdp: Add proper __rcu annotations to redirect map entries date: 11 months ago config: ia64-randconfig-s031-20220522 (https://download.01.org/0day-ci/archive/20220522/202205222029.xpW3PM1y-lkp@intel.com/config) compiler: ia64-linux-gcc (GCC) 11.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.4-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=782347b6bcad07ddb574422e01e22c92e05928c8 git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 782347b6bcad07ddb574422e01e22c92e05928c8 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=ia64 SHELL=/bin/bash kernel/bpf/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@intel.com> sparse warnings: (new ones prefixed by >>) kernel/bpf/devmap.c:561:29: sparse: sparse: incorrect type in assignment (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_netdev *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 assignment (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_netdev *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 space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__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 = 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 = 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 = 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 == BPF_MAP_TYPE_DEVMAP_HASH) { 1020 dev_map_hash_remove_netdev(dtab, netdev); 1021 continue; 1022 } 1023 1024 for (i = 0; i < dtab->map.max_entries; i++) { 1025 struct bpf_dtab_netdev *dev, *odev; 1026 1027 dev = rcu_dereference(dtab->netdev_map[i]); 1028 if (!dev || netdev != dev->dev) 1029 continue; > 1030 odev = unrcu_pointer(cmpxchg(&dtab->netdev_map[i], RCU_INITIALIZER(dev), NULL)); 1031 if (dev == 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 https://01.org/lkp ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression 2022-05-22 12:30 kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression kernel test robot @ 2022-05-23 10:30 ` Toke Høiland-Jørgensen 2022-05-24 20:51 ` Paul E. McKenney 2022-06-01 0:38 ` Luc Van Oostenryck 0 siblings, 2 replies; 9+ messages in thread From: Toke Høiland-Jørgensen @ 2022-05-23 10:30 UTC (permalink / raw) To: kernel test robot Cc: kbuild-all, linux-kernel, Daniel Borkmann, Paul E . McKenney kernel test robot <lkp@intel.com> writes: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: eaea45fc0e7b6ae439526b4a41d91230c8517336 > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 xdp: Add proper __rcu annotations to redirect map entries > date: 11 months ago > config: ia64-randconfig-s031-20220522 (https://download.01.org/0day-ci/archive/20220522/202205222029.xpW3PM1y-lkp@intel.com/config) > compiler: ia64-linux-gcc (GCC) 11.3.0 Hmm, so this is ia64-only? Some kind of macro breakage? Paul, any ideas? -Toke > reproduce: > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # apt-get install sparse > # sparse version: v0.6.4-dirty > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=782347b6bcad07ddb574422e01e22c92e05928c8 > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git fetch --no-tags linus master > git checkout 782347b6bcad07ddb574422e01e22c92e05928c8 > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=ia64 SHELL=/bin/bash kernel/bpf/ > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot <lkp@intel.com> > > > sparse warnings: (new ones prefixed by >>) > kernel/bpf/devmap.c:561:29: sparse: sparse: incorrect type in assignment (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_netdev *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 assignment (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_netdev *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 space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__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 = 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 = 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 = 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 == BPF_MAP_TYPE_DEVMAP_HASH) { > 1020 dev_map_hash_remove_netdev(dtab, netdev); > 1021 continue; > 1022 } > 1023 > 1024 for (i = 0; i < dtab->map.max_entries; i++) { > 1025 struct bpf_dtab_netdev *dev, *odev; > 1026 > 1027 dev = rcu_dereference(dtab->netdev_map[i]); > 1028 if (!dev || netdev != dev->dev) > 1029 continue; >> 1030 odev = unrcu_pointer(cmpxchg(&dtab->netdev_map[i], RCU_INITIALIZER(dev), NULL)); > 1031 if (dev == 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 > https://01.org/lkp ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression 2022-05-23 10:30 ` Toke Høiland-Jørgensen @ 2022-05-24 20:51 ` Paul E. McKenney 2022-06-01 0:38 ` Luc Van Oostenryck 1 sibling, 0 replies; 9+ messages in thread From: Paul E. McKenney @ 2022-05-24 20:51 UTC (permalink / raw) To: Toke Høiland-Jørgensen Cc: kernel test robot, kbuild-all, linux-kernel, Daniel Borkmann On Mon, May 23, 2022 at 12:30:14PM +0200, Toke Høiland-Jørgensen wrote: > kernel test robot <lkp@intel.com> writes: > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > head: eaea45fc0e7b6ae439526b4a41d91230c8517336 > > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 xdp: Add proper __rcu annotations to redirect map entries > > date: 11 months ago > > config: ia64-randconfig-s031-20220522 (https://download.01.org/0day-ci/archive/20220522/202205222029.xpW3PM1y-lkp@intel.com/config) > > compiler: ia64-linux-gcc (GCC) 11.3.0 > > Hmm, so this is ia64-only? Some kind of macro breakage? Paul, any ideas? Line 1030 looks to me like it is doing everything correctly. I am not sure why sparse would care about the architecture, but perhaps it does. The unrcu_pointer() macro has not changed since March of 2020. All I can suggest is to break that line up to make it easier to figure out exactly what sparse is upset about. Thanx, Paul > -Toke > > > reproduce: > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > > chmod +x ~/bin/make.cross > > # apt-get install sparse > > # sparse version: v0.6.4-dirty > > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=782347b6bcad07ddb574422e01e22c92e05928c8 > > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > > git fetch --no-tags linus master > > git checkout 782347b6bcad07ddb574422e01e22c92e05928c8 > > # save the config file > > mkdir build_dir && cp config build_dir/.config > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=ia64 SHELL=/bin/bash kernel/bpf/ > > > > If you fix the issue, kindly add following tag where applicable > > Reported-by: kernel test robot <lkp@intel.com> > > > > > > sparse warnings: (new ones prefixed by >>) > > kernel/bpf/devmap.c:561:29: sparse: sparse: incorrect type in assignment (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_netdev *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 assignment (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_netdev *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 space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression > >>> kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__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 = 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 = 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 = 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 == BPF_MAP_TYPE_DEVMAP_HASH) { > > 1020 dev_map_hash_remove_netdev(dtab, netdev); > > 1021 continue; > > 1022 } > > 1023 > > 1024 for (i = 0; i < dtab->map.max_entries; i++) { > > 1025 struct bpf_dtab_netdev *dev, *odev; > > 1026 > > 1027 dev = rcu_dereference(dtab->netdev_map[i]); > > 1028 if (!dev || netdev != dev->dev) > > 1029 continue; > >> 1030 odev = unrcu_pointer(cmpxchg(&dtab->netdev_map[i], RCU_INITIALIZER(dev), NULL)); > > 1031 if (dev == 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 > > https://01.org/lkp > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression 2022-05-23 10:30 ` Toke Høiland-Jørgensen 2022-05-24 20:51 ` Paul E. McKenney @ 2022-06-01 0:38 ` Luc Van Oostenryck 2022-06-01 10:26 ` Toke Høiland-Jørgensen 1 sibling, 1 reply; 9+ messages in thread From: Luc Van Oostenryck @ 2022-06-01 0:38 UTC (permalink / raw) To: Toke Høiland-Jørgensen Cc: kernel test robot, kbuild-all, linux-kernel, Daniel Borkmann, Paul E . McKenney On Mon, May 23, 2022 at 12:30:14PM +0200, Toke Høiland-Jørgensen wrote: > kernel test robot <lkp@intel.com> writes: > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > head: eaea45fc0e7b6ae439526b4a41d91230c8517336 > > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 xdp: Add proper __rcu annotations to redirect map entries > > date: 11 months ago > > config: ia64-randconfig-s031-20220522 (https://download.01.org/0day-ci/archive/20220522/202205222029.xpW3PM1y-lkp@intel.com/config) > > compiler: ia64-linux-gcc (GCC) 11.3.0 > > Hmm, so this is ia64-only? Some kind of macro breakage? Paul, any ideas? Hi, It's surely IA64's cmpxchg() which contains lines like: _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); -- Luc ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression 2022-06-01 0:38 ` Luc Van Oostenryck @ 2022-06-01 10:26 ` Toke Høiland-Jørgensen 2022-06-01 12:00 ` Luc Van Oostenryck 2022-06-05 16:07 ` [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() Luc Van Oostenryck 0 siblings, 2 replies; 9+ messages in thread From: Toke Høiland-Jørgensen @ 2022-06-01 10:26 UTC (permalink / raw) To: Luc Van Oostenryck Cc: kernel test robot, kbuild-all, linux-kernel, Daniel Borkmann, Paul E . McKenney Luc Van Oostenryck <luc.vanoostenryck@gmail.com> writes: > On Mon, May 23, 2022 at 12:30:14PM +0200, Toke Høiland-Jørgensen wrote: >> kernel test robot <lkp@intel.com> writes: >> >> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >> > head: eaea45fc0e7b6ae439526b4a41d91230c8517336 >> > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 xdp: Add proper __rcu annotations to redirect map entries >> > date: 11 months ago >> > config: ia64-randconfig-s031-20220522 (https://download.01.org/0day-ci/archive/20220522/202205222029.xpW3PM1y-lkp@intel.com/config) >> > compiler: ia64-linux-gcc (GCC) 11.3.0 >> >> Hmm, so this is ia64-only? Some kind of macro breakage? Paul, any ideas? > > Hi, > > It's surely IA64's cmpxchg() which contains lines like: > _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); Oh, right. Hmm, well, if the cmpxchg does an internal cast that complicates things a bit. My immediate thought was to move the unrcu_pointer() inside the calls to cmpxchg(), like: diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 980f8928e977..3b6dc6d34177 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -1098,7 +1098,7 @@ static int dev_map_notification(struct notifier_block *notifier, dev = rcu_dereference(dtab->netdev_map[i]); if (!dev || netdev != dev->dev) continue; - odev = unrcu_pointer(cmpxchg(&dtab->netdev_map[i], RCU_INITIALIZER(dev), NULL)); + odev = cmpxchg(unrcu_pointer(&dtab->netdev_map[i]), dev, NULL); if (dev == odev) call_rcu(&dev->rcu, __dev_map_entry_free); But that seems to confuse sparse because these are ptr-to-ptr constructs: kernel/bpf/devmap.c:1101:40: error: incompatible types in comparison expression (different address spaces): kernel/bpf/devmap.c:1101:40: struct bpf_dtab_netdev [noderef] __rcu *[noderef] __rcu * kernel/bpf/devmap.c:1101:40: struct bpf_dtab_netdev [noderef] __rcu ** kernel/bpf/devmap.c:1101:40: error: incompatible types in comparison expression (different address spaces): kernel/bpf/devmap.c:1101:40: struct bpf_dtab_netdev [noderef] __rcu *[noderef] __rcu * kernel/bpf/devmap.c:1101:40: struct bpf_dtab_netdev [noderef] __rcu ** which I'm not sure how to fix. And not really sure if it's the semantically right thing to do either in this case... -Toke ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression 2022-06-01 10:26 ` Toke Høiland-Jørgensen @ 2022-06-01 12:00 ` Luc Van Oostenryck 2022-06-05 16:07 ` [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() Luc Van Oostenryck 1 sibling, 0 replies; 9+ messages in thread From: Luc Van Oostenryck @ 2022-06-01 12:00 UTC (permalink / raw) To: Toke Høiland-Jørgensen Cc: kernel test robot, kbuild-all, linux-kernel, Daniel Borkmann, Paul E . McKenney, linux-ia64 On Wed, Jun 01, 2022 at 12:26:27PM +0200, Toke Høiland-Jørgensen wrote: > Luc Van Oostenryck <luc.vanoostenryck@gmail.com> writes: > > > On Mon, May 23, 2022 at 12:30:14PM +0200, Toke Høiland-Jørgensen wrote: > >> kernel test robot <lkp@intel.com> writes: > >> > >> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > >> > head: eaea45fc0e7b6ae439526b4a41d91230c8517336 > >> > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 xdp: Add proper __rcu annotations to redirect map entries > >> > date: 11 months ago > >> > config: ia64-randconfig-s031-20220522 (https://download.01.org/0day-ci/archive/20220522/202205222029.xpW3PM1y-lkp@intel.com/config) > >> > compiler: ia64-linux-gcc (GCC) 11.3.0 > >> > >> Hmm, so this is ia64-only? Some kind of macro breakage? Paul, any ideas? > > > > Hi, > > > > It's surely IA64's cmpxchg() which contains lines like: > > _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); > > Oh, right. Hmm, well, if the cmpxchg does an internal cast that > complicates things a bit. My immediate thought was to move the > unrcu_pointer() inside the calls to cmpxchg(), like: > But that seems to confuse sparse because these are ptr-to-ptr > constructs: Yes, that can't work because it applies on the wrong level (same difference as between "int const ** ptr" and "int * const * ptr"). I've taken a quick look and the problem is really to be solved in IA64's macros for cmpxchg() and friends. Two things need to be done: 1) avoid casts like the "(__u64 *) ptr" here above (ideally no cast would be needed but a "(__u64 __force *) ptr" would be pefectly acceptable in such macros. 2) the value returned by these macros must match the type of the pointer and the old/new values. For example, on x86 such macros are written as: ({ __typeof__ (*(ptr)) __ret = (arg); switch (sizeof(*(ptr))) { case ... ... use ptr without dropping the address space .. __ret; )} See, for example, arch/x86/include/asm/cmpxchg.h -- Luc ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() 2022-06-01 10:26 ` Toke Høiland-Jørgensen 2022-06-01 12:00 ` Luc Van Oostenryck @ 2022-06-05 16:07 ` Luc Van Oostenryck 2022-06-05 19:58 ` Paul E. McKenney 2022-06-06 7:53 ` Toke Høiland-Jørgensen 1 sibling, 2 replies; 9+ messages in thread From: Luc Van Oostenryck @ 2022-06-05 16:07 UTC (permalink / raw) To: Arnd Bergmann Cc: Andrew Morton, linux-ia64, linux-kernel, Paul E. McKenney, Luc Van Oostenryck, kernel test robot, Toke Høiland-Jørgensen On IA64, new sparse's warnings where issued after fixing some __rcu annotations in kernel/bpf/. These new warnings are false positives and appear on IA64 because on this architecture, the macros for cmpxchg() and xchg() make casts that ignore sparse annotations. This patch contains the minimal patch to fix this issue: adding a missing cast and some missing '__force'. Link: https://lore.kernel.org/r/20220601120013.bq5a3ynbkc3hngm5@mail Reported-by: kernel test robot <lkp@intel.com> Cc: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> --- Note: This patch is only compile tested on defconfig. The corresponding binary is unchanged (except some .rodata with the kernel version) as it should be. arch/ia64/include/uapi/asm/cmpxchg.h | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/arch/ia64/include/uapi/asm/cmpxchg.h b/arch/ia64/include/uapi/asm/cmpxchg.h index 2c2f3cfeaa77..ca2e02685343 100644 --- a/arch/ia64/include/uapi/asm/cmpxchg.h +++ b/arch/ia64/include/uapi/asm/cmpxchg.h @@ -33,24 +33,24 @@ extern void ia64_xchg_called_with_bad_pointer(void); \ switch (size) { \ case 1: \ - __xchg_result = ia64_xchg1((__u8 *)ptr, x); \ + __xchg_result = ia64_xchg1((__u8 __force *)ptr, x); \ break; \ \ case 2: \ - __xchg_result = ia64_xchg2((__u16 *)ptr, x); \ + __xchg_result = ia64_xchg2((__u16 __force *)ptr, x); \ break; \ \ case 4: \ - __xchg_result = ia64_xchg4((__u32 *)ptr, x); \ + __xchg_result = ia64_xchg4((__u32 __force *)ptr, x); \ break; \ \ case 8: \ - __xchg_result = ia64_xchg8((__u64 *)ptr, x); \ + __xchg_result = ia64_xchg8((__u64 __force *)ptr, x); \ break; \ default: \ ia64_xchg_called_with_bad_pointer(); \ } \ - __xchg_result; \ + (__typeof__ (*(ptr)) __force) __xchg_result; \ }) #ifndef __KERNEL__ @@ -76,42 +76,42 @@ extern long ia64_cmpxchg_called_with_bad_pointer(void); \ switch (size) { \ case 1: \ - _o_ = (__u8) (long) (old); \ + _o_ = (__u8) (long __force) (old); \ break; \ case 2: \ - _o_ = (__u16) (long) (old); \ + _o_ = (__u16) (long __force) (old); \ break; \ case 4: \ - _o_ = (__u32) (long) (old); \ + _o_ = (__u32) (long __force) (old); \ break; \ case 8: \ - _o_ = (__u64) (long) (old); \ + _o_ = (__u64) (long __force) (old); \ break; \ default: \ break; \ } \ switch (size) { \ case 1: \ - _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \ + _r_ = ia64_cmpxchg1_##sem((__u8 __force *) ptr, new, _o_); \ break; \ \ case 2: \ - _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \ + _r_ = ia64_cmpxchg2_##sem((__u16 __force *) ptr, new, _o_); \ break; \ \ case 4: \ - _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \ + _r_ = ia64_cmpxchg4_##sem((__u32 __force *) ptr, new, _o_); \ break; \ \ case 8: \ - _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \ + _r_ = ia64_cmpxchg8_##sem((__u64 __force *) ptr, new, _o_); \ break; \ \ default: \ _r_ = ia64_cmpxchg_called_with_bad_pointer(); \ break; \ } \ - (__typeof__(old)) _r_; \ + (__typeof__(old) __force) _r_; \ }) #define cmpxchg_acq(ptr, o, n) \ -- 2.36.1 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() 2022-06-05 16:07 ` [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() Luc Van Oostenryck @ 2022-06-05 19:58 ` Paul E. McKenney 2022-06-06 7:53 ` Toke Høiland-Jørgensen 1 sibling, 0 replies; 9+ messages in thread From: Paul E. McKenney @ 2022-06-05 19:58 UTC (permalink / raw) To: Luc Van Oostenryck Cc: Arnd Bergmann, Andrew Morton, linux-ia64, linux-kernel, kernel test robot, Toke Høiland-Jørgensen On Sun, Jun 05, 2022 at 06:07:38PM +0200, Luc Van Oostenryck wrote: > On IA64, new sparse's warnings where issued after fixing > some __rcu annotations in kernel/bpf/. > > These new warnings are false positives and appear on IA64 because > on this architecture, the macros for cmpxchg() and xchg() make > casts that ignore sparse annotations. > > This patch contains the minimal patch to fix this issue: > adding a missing cast and some missing '__force'. > > Link: https://lore.kernel.org/r/20220601120013.bq5a3ynbkc3hngm5@mail > Reported-by: kernel test robot <lkp@intel.com> > Cc: Toke Høiland-Jørgensen <toke@redhat.com> > Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Looks good to me! Acked-by: Paul E. McKenney <paulmck@kernel.org> > --- > > Note: This patch is only compile tested on defconfig. The corresponding > binary is unchanged (except some .rodata with the kernel version) > as it should be. > > arch/ia64/include/uapi/asm/cmpxchg.h | 28 ++++++++++++++-------------- > 1 file changed, 14 insertions(+), 14 deletions(-) > > diff --git a/arch/ia64/include/uapi/asm/cmpxchg.h b/arch/ia64/include/uapi/asm/cmpxchg.h > index 2c2f3cfeaa77..ca2e02685343 100644 > --- a/arch/ia64/include/uapi/asm/cmpxchg.h > +++ b/arch/ia64/include/uapi/asm/cmpxchg.h > @@ -33,24 +33,24 @@ extern void ia64_xchg_called_with_bad_pointer(void); > \ > switch (size) { \ > case 1: \ > - __xchg_result = ia64_xchg1((__u8 *)ptr, x); \ > + __xchg_result = ia64_xchg1((__u8 __force *)ptr, x); \ > break; \ > \ > case 2: \ > - __xchg_result = ia64_xchg2((__u16 *)ptr, x); \ > + __xchg_result = ia64_xchg2((__u16 __force *)ptr, x); \ > break; \ > \ > case 4: \ > - __xchg_result = ia64_xchg4((__u32 *)ptr, x); \ > + __xchg_result = ia64_xchg4((__u32 __force *)ptr, x); \ > break; \ > \ > case 8: \ > - __xchg_result = ia64_xchg8((__u64 *)ptr, x); \ > + __xchg_result = ia64_xchg8((__u64 __force *)ptr, x); \ > break; \ > default: \ > ia64_xchg_called_with_bad_pointer(); \ > } \ > - __xchg_result; \ > + (__typeof__ (*(ptr)) __force) __xchg_result; \ > }) > > #ifndef __KERNEL__ > @@ -76,42 +76,42 @@ extern long ia64_cmpxchg_called_with_bad_pointer(void); > \ > switch (size) { \ > case 1: \ > - _o_ = (__u8) (long) (old); \ > + _o_ = (__u8) (long __force) (old); \ > break; \ > case 2: \ > - _o_ = (__u16) (long) (old); \ > + _o_ = (__u16) (long __force) (old); \ > break; \ > case 4: \ > - _o_ = (__u32) (long) (old); \ > + _o_ = (__u32) (long __force) (old); \ > break; \ > case 8: \ > - _o_ = (__u64) (long) (old); \ > + _o_ = (__u64) (long __force) (old); \ > break; \ > default: \ > break; \ > } \ > switch (size) { \ > case 1: \ > - _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \ > + _r_ = ia64_cmpxchg1_##sem((__u8 __force *) ptr, new, _o_); \ > break; \ > \ > case 2: \ > - _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \ > + _r_ = ia64_cmpxchg2_##sem((__u16 __force *) ptr, new, _o_); \ > break; \ > \ > case 4: \ > - _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \ > + _r_ = ia64_cmpxchg4_##sem((__u32 __force *) ptr, new, _o_); \ > break; \ > \ > case 8: \ > - _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \ > + _r_ = ia64_cmpxchg8_##sem((__u64 __force *) ptr, new, _o_); \ > break; \ > \ > default: \ > _r_ = ia64_cmpxchg_called_with_bad_pointer(); \ > break; \ > } \ > - (__typeof__(old)) _r_; \ > + (__typeof__(old) __force) _r_; \ > }) > > #define cmpxchg_acq(ptr, o, n) \ > -- > 2.36.1 > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() 2022-06-05 16:07 ` [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() Luc Van Oostenryck 2022-06-05 19:58 ` Paul E. McKenney @ 2022-06-06 7:53 ` Toke Høiland-Jørgensen 1 sibling, 0 replies; 9+ messages in thread From: Toke Høiland-Jørgensen @ 2022-06-06 7:53 UTC (permalink / raw) To: Luc Van Oostenryck, Arnd Bergmann Cc: Andrew Morton, linux-ia64, linux-kernel, Paul E. McKenney, Luc Van Oostenryck, kernel test robot Luc Van Oostenryck <luc.vanoostenryck@gmail.com> writes: > On IA64, new sparse's warnings where issued after fixing > some __rcu annotations in kernel/bpf/. > > These new warnings are false positives and appear on IA64 because > on this architecture, the macros for cmpxchg() and xchg() make > casts that ignore sparse annotations. > > This patch contains the minimal patch to fix this issue: > adding a missing cast and some missing '__force'. > > Link: https://lore.kernel.org/r/20220601120013.bq5a3ynbkc3hngm5@mail > Reported-by: kernel test robot <lkp@intel.com> > Cc: Toke Høiland-Jørgensen <toke@redhat.com> > Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Ah, thank you for taking care of this! :) Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-06-06 7:53 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-05-22 12:30 kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression kernel test robot 2022-05-23 10:30 ` Toke Høiland-Jørgensen 2022-05-24 20:51 ` Paul E. McKenney 2022-06-01 0:38 ` Luc Van Oostenryck 2022-06-01 10:26 ` Toke Høiland-Jørgensen 2022-06-01 12:00 ` Luc Van Oostenryck 2022-06-05 16:07 ` [PATCH] ia64: fix sparse warnings with cmpxchg() & xchg() Luc Van Oostenryck 2022-06-05 19:58 ` Paul E. McKenney 2022-06-06 7:53 ` Toke Høiland-Jørgensen
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