tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.4.y head: 95a3867e897abd7811196123f81a119a75aba863 commit: 177aa4d14d912a33a4490644987ac499e8bb9e11 [8475/9999] can: mscan: mscan_rx_poll(): fix rx path lockup when returning from polling to irq mode config: powerpc-randconfig-r035-20200719 (attached as .config) compiler: powerpc-linux-gcc (GCC) 7.5.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 177aa4d14d912a33a4490644987ac499e8bb9e11 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-7.5.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): ^~~~~~~~~ include/net/checksum.h: In function 'csum_and_copy_to_user': arch/powerpc/include/asm/uaccess.h:57:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) ^ arch/powerpc/include/asm/uaccess.h:63:3: note: in expansion of macro '__access_ok' __access_ok((__force unsigned long)(addr), (size), get_fs())) ^~~~~~~~~~~ include/net/checksum.h:49:6: note: in expansion of macro 'access_ok' if (access_ok(VERIFY_WRITE, dst, len)) { ^~~~~~~~~ In file included from include/linux/if_ether.h:23:0, from include/uapi/linux/ethtool.h:17, from include/linux/ethtool.h:16, from include/linux/netdevice.h:42, from drivers/net/can/mscan/mscan.c:26: include/linux/skbuff.h: In function 'skb_add_data': include/linux/skbuff.h:2675:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] &csum, from) == copy) { ^~ include/linux/skbuff.h:2679:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] } else if (copy_from_iter(skb_put(skb, copy), copy, from) == copy) ^~ include/linux/skbuff.h: In function 'skb_can_coalesce': include/linux/skbuff.h:2693:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] off == frag->page_offset + skb_frag_size(frag); ^~ include/linux/skbuff.h: In function 'memcpy_from_msg': include/linux/skbuff.h:2921:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return copy_from_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; ^~ include/linux/skbuff.h: In function 'memcpy_to_msg': include/linux/skbuff.h:2926:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; ^~ In file included from include/net/inet_frag.h:4:0, from include/net/netns/ipv4.h:9, from include/net/net_namespace.h:17, from include/linux/netdevice.h:43, from drivers/net/can/mscan/mscan.c:26: include/linux/rhashtable.h: In function 'rht_grow_above_75': include/linux/rhashtable.h:264:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return atomic_read(&ht->nelems) > (tbl->size / 4 * 3) && ^ include/linux/rhashtable.h: In function 'rht_shrink_below_30': include/linux/rhashtable.h:277:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return atomic_read(&ht->nelems) < (tbl->size * 3 / 10) && ^ include/linux/rhashtable.h: In function 'rht_grow_above_100': include/linux/rhashtable.h:289:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return atomic_read(&ht->nelems) > tbl->size && ^ include/linux/rhashtable.h: In function 'rht_grow_above_max': include/linux/rhashtable.h:302:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] atomic_read(&ht->nelems) >= ht->p.insecure_max_entries; ^~ In file included from drivers/net/can/mscan/mscan.c:26:0: include/linux/netdevice.h: In function '__skb_gro_checksum_validate_needed': include/linux/netdevice.h:2389:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] skb_checksum_start_offset(skb) < ^ In file included from include/linux/bug.h:4:0, from include/linux/thread_info.h:11, from include/asm-generic/preempt.h:4, from arch/powerpc/include/generated/asm/preempt.h:1, from include/linux/preempt.h:59, from include/linux/spinlock.h:50, from include/linux/seqlock.h:35, from include/linux/time.h:5, from include/linux/stat.h:18, from include/linux/module.h:10, from drivers/net/can/mscan/mscan.c:23: include/linux/netdevice.h: In function 'get_netdev_rx_queue_index': include/linux/netdevice.h:3027:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] BUG_ON(index >= dev->num_rx_queues); ^ arch/powerpc/include/asm/bug.h:75:27: note: in definition of macro 'BUG_ON' if (__builtin_constant_p(x)) { \ ^ include/linux/netdevice.h:3027:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] BUG_ON(index >= dev->num_rx_queues); ^ arch/powerpc/include/asm/bug.h:76:7: note: in definition of macro 'BUG_ON' if (x) \ ^ include/linux/netdevice.h:3027:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] BUG_ON(index >= dev->num_rx_queues); ^ arch/powerpc/include/asm/bug.h:84:25: note: in definition of macro 'BUG_ON' "r" ((__force long)(x))); \ ^ In file included from drivers/net/can/mscan/mscan.c:26:0: include/linux/netdevice.h: In function 'netif_msg_init': include/linux/netdevice.h:3301:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (debug_value < 0 || debug_value >= (sizeof(u32) * 8)) ^~ In file included from include/linux/linkage.h:4:0, from include/linux/kernel.h:6, from drivers/net/can/mscan/mscan.c:22: drivers/net/can/mscan/mscan.c: In function 'mscan_rx_poll': # define likely(x) __builtin_expect(!!(x), 1) ^ drivers/net/can/mscan/mscan.c:426:7: note: in expansion of macro 'likely' if (likely(napi_complete_done(&priv->napi, work_done))) { ^~~~~~ drivers/net/can/mscan/mscan.c: In function 'mscan_start_xmit': drivers/net/can/mscan/mscan.c:222:3: warning: this statement may fall through [-Wimplicit-fallthrough=] netif_stop_queue(dev); ^~~~~~~~~~~~~~~~~~~~~ drivers/net/can/mscan/mscan.c:223:2: note: here case 2: ^~~~ vim +181 include/linux/compiler.h 2bcd521a684cc9 Steven Rostedt 2008-11-21 179 1f0d69a9fc815d Steven Rostedt 2008-11-12 180 #else ^1da177e4c3f41 Linus Torvalds 2005-04-16 @181 # define likely(x) __builtin_expect(!!(x), 1) ^1da177e4c3f41 Linus Torvalds 2005-04-16 182 # define unlikely(x) __builtin_expect(!!(x), 0) 1f0d69a9fc815d Steven Rostedt 2008-11-12 183 #endif ^1da177e4c3f41 Linus Torvalds 2005-04-16 184 :::::: The code at line 181 was first introduced by commit :::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2 :::::: TO: Linus Torvalds <torvalds(a)ppc970.osdl.org&gt; :::::: CC: Linus Torvalds <torvalds(a)ppc970.osdl.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org