tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 671176b0016c80b3943cb5387312c886aba3308d commit: 1d881c0431850a197c9164c4b8009b48481b9263 [10174/10581] mm: cma: print region name on failure config: microblaze-randconfig-r021-20210212 (attached as .config) compiler: microblaze-linux-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/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 1d881c0431850a197c9164c4b8009b48481b9263 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=microblaze 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 include/linux/printk.h:7, from include/linux/kernel.h:16, from include/asm-generic/bug.h:20, from ./arch/microblaze/include/generated/asm/bug.h:1, 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 mm/cma.c:24: mm/cma.c: In function 'cma_alloc': 5 | #define KERN_SOH "\001" /* ASCII Start Of Header */ | ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' 11 | #define KERN_ERR KERN_SOH "3" /* error conditions */ | ^~~~~~~~ include/linux/printk.h:343:9: note: in expansion of macro 'KERN_ERR' 343 | printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~ mm/cma.c:503:3: note: in expansion of macro 'pr_err' 503 | pr_err("%s: %s: alloc failed, req-size: %zu pages, ret: %d\n", | ^~~~~~ mm/cma.c:503:45: note: format string is defined here 503 | pr_err("%s: %s: alloc failed, req-size: %zu pages, ret: %d\n", | ~~^ | | | unsigned int | %lu vim +5 include/linux/kern_levels.h 314ba3520e513a Joe Perches 2012-07-30 4 04d2c8c83d0e3a Joe Perches 2012-07-30 @5 #define KERN_SOH "\001" /* ASCII Start Of Header */ 04d2c8c83d0e3a Joe Perches 2012-07-30 6 #define KERN_SOH_ASCII '\001' 04d2c8c83d0e3a Joe Perches 2012-07-30 7 :::::: The code at line 5 was first introduced by commit :::::: 04d2c8c83d0e3ac5f78aeede51babb3236200112 printk: convert the format for KERN_<LEVEL> to a 2 byte pattern :::::: TO: Joe Perches <joe(a)perches.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org