tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git queue-5.4 head: b24ca39180f94e05ffdb3647ca2386841aa7fad7 commit: 36c0f4438e873a61dd5f0cbe2695b826e18f93d3 [7/8] mm/memcg: set memcg when splitting page config: powerpc-randconfig-r021-20210317 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 6db3ab2903f42712f44000afb5aa467efbd25f35) 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 # install powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-linux-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-linux-stable queue-5.4 git checkout 36c0f4438e873a61dd5f0cbe2695b826e18f93d3 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang 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 >>): In file included from include/linux/hardirq.h:9: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:605: arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:602:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:141:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insw' #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/page_alloc.c:20: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:9: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:605: arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:602:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:143:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:544:56: note: expanded from macro '__do_insl' #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/page_alloc.c:20: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:9: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:605: arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:602:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:145:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsb' #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/page_alloc.c:20: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:9: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:605: arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:602:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:147:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsw' #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/page_alloc.c:20: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:9: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:605: arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:602:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:149:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:547:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ mm/page_alloc.c:2478:5: warning: no previous prototype for function 'find_suitable_fallback' [-Wmissing-prototypes] int find_suitable_fallback(struct free_area *area, unsigned int order, ^ mm/page_alloc.c:2478:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int find_suitable_fallback(struct free_area *area, unsigned int order, ^ static split_page_memcg(page, 1 << order); ^ mm/page_alloc.c:3390:15: warning: no previous prototype for function 'should_fail_alloc_page' [-Wmissing-prototypes] noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) ^ mm/page_alloc.c:3390:10: note: declare 'static' if the function is not intended to be used outside of this translation unit noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) ^ static mm/page_alloc.c:6053:23: warning: no previous prototype for function 'memmap_init' [-Wmissing-prototypes] void __meminit __weak memmap_init(unsigned long size, int nid, ^ mm/page_alloc.c:6053:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __meminit __weak memmap_init(unsigned long size, int nid, ^ static 15 warnings and 1 error generated. vim +/split_page_memcg +3135 mm/page_alloc.c 3116 3117 /* 3118 * split_page takes a non-compound higher-order page, and splits it into 3119 * n (1<<order) sub-pages: page[0..n] 3120 * Each sub-page must be freed individually. 3121 * 3122 * Note: this is probably too low level an operation for use in drivers. 3123 * Please consult with lkml before using this in your driver. 3124 */ 3125 void split_page(struct page *page, unsigned int order) 3126 { 3127 int i; 3128 3129 VM_BUG_ON_PAGE(PageCompound(page), page); 3130 VM_BUG_ON_PAGE(!page_count(page), page); 3131 3132 for (i = 1; i < (1 << order); i++) 3133 set_page_refcounted(page + i); 3134 split_page_owner(page, 1 << order); 3136 } 3137 EXPORT_SYMBOL_GPL(split_page); 3138 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org