tree: https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git atomics/arch-atomic head: 2a8926b2ab0b5a1bdc6a7139c9b011e9d4ff14fa commit: 4e146fa6d26c7c6959f8cc7a385958d7b63f0ff0 [15/33] locking/atomic: arm: move to ARCH_ATOMIC config: arm-randconfig-r004-20210513 (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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 # https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/commit/?id... git remote add mark-rutland https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git git fetch --no-tags mark-rutland atomics/arch-atomic git checkout 4e146fa6d26c7c6959f8cc7a385958d7b63f0ff0 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross W=1 ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from drivers/xen/grant-table.c:67: 24 | #define sync_cmpxchg cmpxchg | In file included from include/linux/atomic.h:82, from include/asm-generic/bitops/lock.h:5, from arch/arm/include/asm/bitops.h:243, from include/linux/bitops.h:32, from include/linux/kernel.h:12, from include/asm-generic/bug.h:20, from arch/arm/include/asm/bug.h:60, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/mm.h:9, from include/linux/memblock.h:13, from drivers/xen/grant-table.c:36: include/asm-generic/atomic-instrumented.h:1810: note: this is the location of the previous definition 1810 | #define sync_cmpxchg(ptr, ...) \ | -- In file included from drivers/xen/events/events_2l.c:14: 24 | #define sync_cmpxchg cmpxchg | In file included from include/linux/atomic.h:82, from include/asm-generic/bitops/lock.h:5, from arch/arm/include/asm/bitops.h:243, from include/linux/bitops.h:32, from include/linux/kernel.h:12, from include/linux/interrupt.h:6, from drivers/xen/events/events_2l.c:11: include/asm-generic/atomic-instrumented.h:1810: note: this is the location of the previous definition 1810 | #define sync_cmpxchg(ptr, ...) \ | drivers/xen/events/events_2l.c:264:13: warning: no previous prototype for 'xen_debug_interrupt' [-Wmissing-prototypes] 264 | irqreturn_t xen_debug_interrupt(int irq, void *dev_id) | ^~~~~~~~~~~~~~~~~~~ vim +/sync_cmpxchg +24 arch/arm/include/asm/sync_bitops.h e54d2f61528165 Stefano Stabellini 2012-08-08 6 e54d2f61528165 Stefano Stabellini 2012-08-08 7 /* sync_bitops functions are equivalent to the SMP implementation of the e54d2f61528165 Stefano Stabellini 2012-08-08 8 * original functions, independently from CONFIG_SMP being defined. e54d2f61528165 Stefano Stabellini 2012-08-08 9 * e54d2f61528165 Stefano Stabellini 2012-08-08 10 * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But e54d2f61528165 Stefano Stabellini 2012-08-08 11 * under Xen you might be communicating with a completely external entity e54d2f61528165 Stefano Stabellini 2012-08-08 12 * who might be on another CPU (e.g. two uniprocessor guests communicating e54d2f61528165 Stefano Stabellini 2012-08-08 13 * via event channels and grant tables). So we need a variant of the bit e54d2f61528165 Stefano Stabellini 2012-08-08 14 * ops which are SMP safe even on a UP kernel. e54d2f61528165 Stefano Stabellini 2012-08-08 15 */ e54d2f61528165 Stefano Stabellini 2012-08-08 16 e54d2f61528165 Stefano Stabellini 2012-08-08 17 #define sync_set_bit(nr, p) _set_bit(nr, p) e54d2f61528165 Stefano Stabellini 2012-08-08 18 #define sync_clear_bit(nr, p) _clear_bit(nr, p) e54d2f61528165 Stefano Stabellini 2012-08-08 19 #define sync_change_bit(nr, p) _change_bit(nr, p) e54d2f61528165 Stefano Stabellini 2012-08-08 20 #define sync_test_and_set_bit(nr, p) _test_and_set_bit(nr, p) e54d2f61528165 Stefano Stabellini 2012-08-08 21 #define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p) e54d2f61528165 Stefano Stabellini 2012-08-08 22 #define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p) e54d2f61528165 Stefano Stabellini 2012-08-08 23 #define sync_test_bit(nr, addr) test_bit(nr, addr) e54d2f61528165 Stefano Stabellini 2012-08-08 @24 #define sync_cmpxchg cmpxchg e54d2f61528165 Stefano Stabellini 2012-08-08 25 e54d2f61528165 Stefano Stabellini 2012-08-08 26 :::::: The code at line 24 was first introduced by commit :::::: e54d2f61528165bbe0e5f628b111eab3be31c3b5 xen/arm: sync_bitops :::::: TO: Stefano Stabellini <stefano.stabellini(a)eu.citrix.com&gt; :::::: CC: Stefano Stabellini <stefano.stabellini(a)eu.citrix.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org