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* [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
@ 2021-06-26  8:41 kernel test robot
  2021-06-26 10:00 ` Toke Høiland-Jørgensen
  0 siblings, 1 reply; 9+ messages in thread
From: kernel test robot @ 2021-06-26  8:41 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 6791 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
head:   a196fa78a26571359740f701cf30d774eb8a72cb
commit: 782347b6bcad07ddb574422e01e22c92e05928c8 [15/30] xdp: Add proper __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/sbin/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=782347b6bcad07ddb574422e01e22c92e05928c8
        git remote add bpf-next https://git.kernel.org/pub/scm/linux/kernel/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=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 

If you fix the issue, kindly add following tag as appropriate
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, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-26  8:41 [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression kernel test robot
@ 2021-06-26 10:00 ` Toke Høiland-Jørgensen
  2021-06-28 15:53   ` Paul E. McKenney
  0 siblings, 1 reply; 9+ messages in thread
From: Toke Høiland-Jørgensen @ 2021-06-26 10:00 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 7059 bytes --]

+Paul - any idea why unrcu_pointer() isn't working here?

-Toke

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
> head:   a196fa78a26571359740f701cf30d774eb8a72cb
> commit: 782347b6bcad07ddb574422e01e22c92e05928c8 [15/30] xdp: Add proper __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/sbin/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=782347b6bcad07ddb574422e01e22c92e05928c8
>         git remote add bpf-next https://git.kernel.org/pub/scm/linux/kernel/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=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 
>
> If you fix the issue, kindly add following tag as appropriate
> 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, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-26 10:00 ` Toke Høiland-Jørgensen
@ 2021-06-28 15:53   ` Paul E. McKenney
  2021-06-28 22:42     ` Toke Høiland-Jørgensen
  0 siblings, 1 reply; 9+ messages in thread
From: Paul E. McKenney @ 2021-06-28 15:53 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 8476 bytes --]

On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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.git master
> > head:   a196fa78a26571359740f701cf30d774eb8a72cb
> > commit: 782347b6bcad07ddb574422e01e22c92e05928c8 [15/30] xdp: Add proper __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/sbin/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=782347b6bcad07ddb574422e01e22c92e05928c8
> >         git remote add bpf-next https://git.kernel.org/pub/scm/linux/kernel/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=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 
> >
> > If you fix the issue, kindly add following tag as appropriate
> > 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, Intel Corporation
> > https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
> 

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-28 15:53   ` Paul E. McKenney
@ 2021-06-28 22:42     ` Toke Høiland-Jørgensen
  2021-06-28 22:53       ` Paul E. McKenney
  0 siblings, 1 reply; 9+ messages in thread
From: Toke Høiland-Jørgensen @ 2021-06-28 22:42 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 1292 bytes --]

"Paul E. McKenney" <paulmck@kernel.org> writes:

> On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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 *

Hmm, but those shouldn't be there either. Seems I missed those when
rebasing, will send a follow-up patch...

-Toke

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-28 22:42     ` Toke Høiland-Jørgensen
@ 2021-06-28 22:53       ` Paul E. McKenney
  2021-06-29  8:47         ` Chen, Rong A
  0 siblings, 1 reply; 9+ messages in thread
From: Paul E. McKenney @ 2021-06-28 22:53 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 1513 bytes --]

On Tue, Jun 29, 2021 at 12:42:52AM +0200, Toke Høiland-Jørgensen wrote:
> "Paul E. McKenney" <paulmck@kernel.org> writes:
> 
> > On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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 *
> 
> Hmm, but those shouldn't be there either. Seems I missed those when
> rebasing, will send a follow-up patch...

Just check out different versions of sparse and average the results?  ;-)

							Thanx, Paul

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-28 22:53       ` Paul E. McKenney
@ 2021-06-29  8:47         ` Chen, Rong A
  2021-06-29 16:57           ` Paul E. McKenney
  0 siblings, 1 reply; 9+ messages in thread
From: Chen, Rong A @ 2021-06-29  8:47 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 4065 bytes --]



On 6/29/2021 6:53 AM, Paul E. McKenney wrote:
> On Tue, Jun 29, 2021 at 12:42:52AM +0200, Toke Høiland-Jørgensen wrote:
>> "Paul E. McKenney" <paulmck@kernel.org> writes:
>>
>>> On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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 *
>>
>> Hmm, but those shouldn't be there either. Seems I missed those when
>> rebasing, will send a follow-up patch...
> 
> Just check out different versions of sparse and average the results?  ;-)
> 
> 							Thanx, Paul

Hi Paul,

I tested the original attached config with the reproduce step, and I can 
reproduce the warning:

$ COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 
CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 kernel/bpf/
...
kernel/bpf/devmap.c:561:29: sparse: warning: incorrect type in 
assignment (different address spaces)
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: warning: incorrect type in 
assignment (different address spaces)
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: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression
kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space 
'__rcu' of expression

and sparse is from latest master branch:
$ sparse --version
v0.6.3-341-g8af24329


Best Regards,
Rong Chen

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-29  8:47         ` Chen, Rong A
@ 2021-06-29 16:57           ` Paul E. McKenney
  2021-06-30  7:31             ` Chen, Rong A
  0 siblings, 1 reply; 9+ messages in thread
From: Paul E. McKenney @ 2021-06-29 16:57 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 4574 bytes --]

On Tue, Jun 29, 2021 at 04:47:17PM +0800, Chen, Rong A wrote:
> 
> 
> On 6/29/2021 6:53 AM, Paul E. McKenney wrote:
> > On Tue, Jun 29, 2021 at 12:42:52AM +0200, Toke Høiland-Jørgensen wrote:
> > > "Paul E. McKenney" <paulmck@kernel.org> writes:
> > > 
> > > > On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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 *
> > > 
> > > Hmm, but those shouldn't be there either. Seems I missed those when
> > > rebasing, will send a follow-up patch...
> > 
> > Just check out different versions of sparse and average the results?  ;-)
> > 
> > 							Thanx, Paul
> 
> Hi Paul,
> 
> I tested the original attached config with the reproduce step, and I can
> reproduce the warning:
> 
> $ COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1
> CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 kernel/bpf/
> ...
> kernel/bpf/devmap.c:561:29: sparse: warning: incorrect type in assignment
> (different address spaces)
> 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: warning: incorrect type in assignment
> (different address spaces)
> 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: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> '__rcu' of expression
> 
> and sparse is from latest master branch:
> $ sparse --version
> v0.6.3-341-g8af24329

OK, we really are running the same sparse.  And even the same gcc.

I did only a "make defconfig" followed by a "C=2" native build
on x86.  Is your "ARCH=ia64" required, or does sparse also get
you these same errors on x86?

							Thanx, Paul

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-29 16:57           ` Paul E. McKenney
@ 2021-06-30  7:31             ` Chen, Rong A
  2021-06-30 15:38               ` Paul E. McKenney
  0 siblings, 1 reply; 9+ messages in thread
From: Chen, Rong A @ 2021-06-30  7:31 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 5547 bytes --]



On 6/30/2021 12:57 AM, Paul E. McKenney wrote:
> On Tue, Jun 29, 2021 at 04:47:17PM +0800, Chen, Rong A wrote:
>>
>>
>> On 6/29/2021 6:53 AM, Paul E. McKenney wrote:
>>> On Tue, Jun 29, 2021 at 12:42:52AM +0200, Toke Høiland-Jørgensen wrote:
>>>> "Paul E. McKenney" <paulmck@kernel.org> writes:
>>>>
>>>>> On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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 *
>>>>
>>>> Hmm, but those shouldn't be there either. Seems I missed those when
>>>> rebasing, will send a follow-up patch...
>>>
>>> Just check out different versions of sparse and average the results?  ;-)
>>>
>>> 							Thanx, Paul
>>
>> Hi Paul,
>>
>> I tested the original attached config with the reproduce step, and I can
>> reproduce the warning:
>>
>> $ COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1
>> CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 kernel/bpf/
>> ...
>> kernel/bpf/devmap.c:561:29: sparse: warning: incorrect type in assignment
>> (different address spaces)
>> 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: warning: incorrect type in assignment
>> (different address spaces)
>> 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: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>> kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
>> '__rcu' of expression
>>
>> and sparse is from latest master branch:
>> $ sparse --version
>> v0.6.3-341-g8af24329
> 
> OK, we really are running the same sparse.  And even the same gcc.
> 
> I did only a "make defconfig" followed by a "C=2" native build
> on x86.  Is your "ARCH=ia64" required, or does sparse also get
> you these same errors on x86?
> 
> 							Thanx, Paul
> 

Hi Paul,

I can't get the error on x86:

$ make --jobs=16 C=1 CF=-fdiagnostic-prefix -D__CHECK_ENDIAN__ W=1 
ARCH=x86_64 kernel/bpf/
   DESCEND objtool
   CALL    scripts/atomic/check-atomics.sh
   CALL    scripts/checksyscalls.sh
   CC      kernel/bpf/devmap.o
   CHECK   kernel/bpf/devmap.c
kernel/bpf/devmap.c:561:29: sparse: warning: incorrect type in 
assignment (different address spaces)
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: warning: incorrect type in 
assignment (different address spaces)
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 *
   AR      kernel/bpf/built-in.a

Best Regards,
Rong Chen

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression
  2021-06-30  7:31             ` Chen, Rong A
@ 2021-06-30 15:38               ` Paul E. McKenney
  0 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2021-06-30 15:38 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 6428 bytes --]

On Wed, Jun 30, 2021 at 03:31:57PM +0800, Chen, Rong A wrote:
> 
> 
> On 6/30/2021 12:57 AM, Paul E. McKenney wrote:
> > On Tue, Jun 29, 2021 at 04:47:17PM +0800, Chen, Rong A wrote:
> > > 
> > > 
> > > On 6/29/2021 6:53 AM, Paul E. McKenney wrote:
> > > > On Tue, Jun 29, 2021 at 12:42:52AM +0200, Toke Høiland-Jørgensen wrote:
> > > > > "Paul E. McKenney" <paulmck@kernel.org> writes:
> > > > > 
> > > > > > On Sat, Jun 26, 2021 at 12:00:55PM +0200, Toke Høiland-Jørgensen 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 (different 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 (different 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 *
> > > > > 
> > > > > Hmm, but those shouldn't be there either. Seems I missed those when
> > > > > rebasing, will send a follow-up patch...
> > > > 
> > > > Just check out different versions of sparse and average the results?  ;-)
> > > > 
> > > > 							Thanx, Paul
> > > 
> > > Hi Paul,
> > > 
> > > I tested the original attached config with the reproduce step, and I can
> > > reproduce the warning:
> > > 
> > > $ COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1
> > > CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=ia64 kernel/bpf/
> > > ...
> > > kernel/bpf/devmap.c:561:29: sparse: warning: incorrect type in assignment
> > > (different address spaces)
> > > 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: warning: incorrect type in assignment
> > > (different address spaces)
> > > 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: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > kernel/bpf/devmap.c:1030:40: sparse: warning: cast removes address space
> > > '__rcu' of expression
> > > 
> > > and sparse is from latest master branch:
> > > $ sparse --version
> > > v0.6.3-341-g8af24329
> > 
> > OK, we really are running the same sparse.  And even the same gcc.
> > 
> > I did only a "make defconfig" followed by a "C=2" native build
> > on x86.  Is your "ARCH=ia64" required, or does sparse also get
> > you these same errors on x86?
> > 
> > 							Thanx, Paul
> > 
> 
> Hi Paul,
> 
> I can't get the error on x86:
> 
> $ make --jobs=16 C=1 CF=-fdiagnostic-prefix -D__CHECK_ENDIAN__ W=1
> ARCH=x86_64 kernel/bpf/
>   DESCEND objtool
>   CALL    scripts/atomic/check-atomics.sh
>   CALL    scripts/checksyscalls.sh
>   CC      kernel/bpf/devmap.o
>   CHECK   kernel/bpf/devmap.c
> kernel/bpf/devmap.c:561:29: sparse: warning: incorrect type in assignment
> (different address spaces)
> 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: warning: incorrect type in assignment
> (different address spaces)
> 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 *
>   AR      kernel/bpf/built-in.a

This looks similar to what I saw, and I believe that Toke sent out a
patch for these.

So this is likely to be an architecture-specific bug in IA64, correct?

I was going to add the IA64 maintainers on CC, but:

IA64 (Itanium) PLATFORM
L:	linux-ia64(a)vger.kernel.org
S:	Orphan
F:	Documentation/ia64/
F:	arch/ia64/

Over to you in your role as an Intel employee!  ;-)

							Thanx, Paul

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2021-06-30 15:38 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-26  8:41 [bpf-next:master 15/30] kernel/bpf/devmap.c:1030:40: sparse: sparse: cast removes address space '__rcu' of expression kernel test robot
2021-06-26 10:00 ` Toke Høiland-Jørgensen
2021-06-28 15:53   ` Paul E. McKenney
2021-06-28 22:42     ` Toke Høiland-Jørgensen
2021-06-28 22:53       ` Paul E. McKenney
2021-06-29  8:47         ` Chen, Rong A
2021-06-29 16:57           ` Paul E. McKenney
2021-06-30  7:31             ` Chen, Rong A
2021-06-30 15:38               ` Paul E. McKenney

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