Hi Marco, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v5.1 next-20190517] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Marco-Elver/mm-kasan-Print-frame-description-for-stack-bugs/20190519-040214 config: xtensa-allyesconfig (attached as .config) compiler: xtensa-linux-gcc (GCC) 8.1.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree GCC_VERSION=8.1.0 make.cross ARCH=xtensa If you fix the issue, kindly add following tag Reported-by: kbuild test robot All warnings (new ones prefixed by >>): In file included from include/linux/printk.h:7, from include/linux/kernel.h:15, from include/linux/kallsyms.h:10, from include/linux/ftrace.h:11, from mm/kasan/report.c:18: mm/kasan/report.c: In function 'print_decoded_frame_descr': >> include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of type 'size_t', but argument 2 has type 'long unsigned int' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' #define KERN_ERR KERN_SOH "3" /* error conditions */ ^~~~~~~~ include/linux/printk.h:304:9: note: in expansion of macro 'KERN_ERR' printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~ mm/kasan/report.c:233:2: note: in expansion of macro 'pr_err' pr_err("this frame has %zu %s:\n", num_objects, ^~~~~~ mm/kasan/report.c:233:27: note: format string is defined here pr_err("this frame has %zu %s:\n", num_objects, ~~^ %lu In file included from include/linux/printk.h:7, from include/linux/kernel.h:15, from include/linux/kallsyms.h:10, from include/linux/ftrace.h:11, from mm/kasan/report.c:18: >> include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of type 'size_t', but argument 2 has type 'long unsigned int' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' #define KERN_ERR KERN_SOH "3" /* error conditions */ ^~~~~~~~ include/linux/printk.h:304:9: note: in expansion of macro 'KERN_ERR' printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~ mm/kasan/report.c:260:3: note: in expansion of macro 'pr_err' pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ^~~~~~ mm/kasan/report.c:260:15: note: format string is defined here pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ~~^ %lu In file included from include/linux/printk.h:7, from include/linux/kernel.h:15, from include/linux/kallsyms.h:10, from include/linux/ftrace.h:11, from mm/kasan/report.c:18: include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of type 'size_t', but argument 3 has type 'long unsigned int' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' #define KERN_ERR KERN_SOH "3" /* error conditions */ ^~~~~~~~ include/linux/printk.h:304:9: note: in expansion of macro 'KERN_ERR' printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~ mm/kasan/report.c:260:3: note: in expansion of macro 'pr_err' pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ^~~~~~ mm/kasan/report.c:260:20: note: format string is defined here pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ~~^ %lu -- In file included from include/linux/printk.h:7, from include/linux/kernel.h:15, from include/linux/kallsyms.h:10, from include/linux/ftrace.h:11, from mm//kasan/report.c:18: mm//kasan/report.c: In function 'print_decoded_frame_descr': >> include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of type 'size_t', but argument 2 has type 'long unsigned int' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' #define KERN_ERR KERN_SOH "3" /* error conditions */ ^~~~~~~~ include/linux/printk.h:304:9: note: in expansion of macro 'KERN_ERR' printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~ mm//kasan/report.c:233:2: note: in expansion of macro 'pr_err' pr_err("this frame has %zu %s:\n", num_objects, ^~~~~~ mm//kasan/report.c:233:27: note: format string is defined here pr_err("this frame has %zu %s:\n", num_objects, ~~^ %lu In file included from include/linux/printk.h:7, from include/linux/kernel.h:15, from include/linux/kallsyms.h:10, from include/linux/ftrace.h:11, from mm//kasan/report.c:18: >> include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of type 'size_t', but argument 2 has type 'long unsigned int' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' #define KERN_ERR KERN_SOH "3" /* error conditions */ ^~~~~~~~ include/linux/printk.h:304:9: note: in expansion of macro 'KERN_ERR' printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~ mm//kasan/report.c:260:3: note: in expansion of macro 'pr_err' pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ^~~~~~ mm//kasan/report.c:260:15: note: format string is defined here pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ~~^ %lu In file included from include/linux/printk.h:7, from include/linux/kernel.h:15, from include/linux/kallsyms.h:10, from include/linux/ftrace.h:11, from mm//kasan/report.c:18: include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of type 'size_t', but argument 3 has type 'long unsigned int' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^~~~~~ include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH' #define KERN_ERR KERN_SOH "3" /* error conditions */ ^~~~~~~~ include/linux/printk.h:304:9: note: in expansion of macro 'KERN_ERR' printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~ mm//kasan/report.c:260:3: note: in expansion of macro 'pr_err' pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ^~~~~~ mm//kasan/report.c:260:20: note: format string is defined here pr_err(" [%zu, %zu) '%s'", offset, offset + size, token); ~~^ %lu vim +5 include/linux/kern_levels.h 314ba352 Joe Perches 2012-07-30 4 04d2c8c8 Joe Perches 2012-07-30 @5 #define KERN_SOH "\001" /* ASCII Start Of Header */ 04d2c8c8 Joe Perches 2012-07-30 6 #define KERN_SOH_ASCII '\001' 04d2c8c8 Joe Perches 2012-07-30 7 :::::: The code at line 5 was first introduced by commit :::::: 04d2c8c83d0e3ac5f78aeede51babb3236200112 printk: convert the format for KERN_ to a 2 byte pattern :::::: TO: Joe Perches :::::: CC: Linus Torvalds --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation