Hi Tony, I love your patch! Perhaps something to improve: [auto build test WARNING on kvms390/next] [also build test WARNING on linus/master v5.7] [cannot apply to s390/features linux/master next-20200605] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Tony-Krowiak/s390-vfio-ap-dynamic-configuration-support/20200606-054350 base: https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git next config: s390-randconfig-r025-20200605 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 6dd738e2f0609f7d3313b574a1d471263d2d3ba1) 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 s390 cross compiling tool for clang build # apt-get install binutils-s390-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>, old ones prefixed by <<): include/uapi/linux/swab.h:19:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x000000ffUL) << 24) | ^ In file included from drivers/s390/crypto/ap_bus.c:28: In file included from arch/s390/include/asm/airq.h:14: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | ^ In file included from drivers/s390/crypto/ap_bus.c:28: In file included from arch/s390/include/asm/airq.h:14: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | ^ In file included from drivers/s390/crypto/ap_bus.c:28: In file included from arch/s390/include/asm/airq.h:14: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0xff000000UL) >> 24))) ^ In file included from drivers/s390/crypto/ap_bus.c:28: In file included from arch/s390/include/asm/airq.h:14: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32' __fswab32(x)) ^ In file included from drivers/s390/crypto/ap_bus.c:28: In file included from arch/s390/include/asm/airq.h:14: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:503:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:513:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew(cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:523:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel(cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:585:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:593:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:601:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:610:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:619:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:628:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> drivers/s390/crypto/ap_bus.c:1106:5: warning: no previous prototype for function '__verify_card_reservations' [-Wmissing-prototypes] int __verify_card_reservations(struct device_driver *drv, void *data) ^ drivers/s390/crypto/ap_bus.c:1106:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __verify_card_reservations(struct device_driver *drv, void *data) ^ static >> drivers/s390/crypto/ap_bus.c:1195:5: warning: no previous prototype for function '__verify_queue_reservations' [-Wmissing-prototypes] int __verify_queue_reservations(struct device_driver *drv, void *data) ^ drivers/s390/crypto/ap_bus.c:1195:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __verify_queue_reservations(struct device_driver *drv, void *data) ^ static 22 warnings generated. vim +/__verify_card_reservations +1106 drivers/s390/crypto/ap_bus.c 1105 > 1106 int __verify_card_reservations(struct device_driver *drv, void *data) 1107 { 1108 int rc = 0; 1109 struct ap_driver *ap_drv = to_ap_drv(drv); 1110 unsigned long *newapm = (unsigned long *)data; 1111 1112 /* 1113 * No need to verify whether the driver is using the queues if it is the 1114 * default driver. 1115 */ 1116 if (ap_drv->flags & AP_DRIVER_FLAG_DEFAULT) 1117 return 0; 1118 1119 /* The non-default driver's module must be loaded */ 1120 if (!try_module_get(drv->owner)) 1121 return 0; 1122 1123 if (ap_drv->in_use) 1124 if (ap_drv->in_use(newapm, ap_perms.aqm)) 1125 rc = -EADDRINUSE; 1126 1127 module_put(drv->owner); 1128 1129 return rc; 1130 } 1131 1132 static int apmask_commit(unsigned long *newapm) 1133 { 1134 int rc; 1135 unsigned long reserved[BITS_TO_LONGS(AP_DEVICES)]; 1136 1137 /* 1138 * Check if any bits in the apmask have been set which will 1139 * result in queues being removed from non-default drivers 1140 */ 1141 if (bitmap_andnot(reserved, newapm, ap_perms.apm, AP_DEVICES)) { 1142 rc = bus_for_each_drv(&ap_bus_type, NULL, reserved, 1143 __verify_card_reservations); 1144 if (rc) 1145 return rc; 1146 } 1147 1148 memcpy(ap_perms.apm, newapm, APMASKSIZE); 1149 1150 return 0; 1151 } 1152 1153 static ssize_t apmask_store(struct bus_type *bus, const char *buf, 1154 size_t count) 1155 { 1156 int rc; 1157 DECLARE_BITMAP(newapm, AP_DEVICES); 1158 1159 if (mutex_lock_interruptible(&ap_perms_mutex)) 1160 return -ERESTARTSYS; 1161 1162 rc = ap_parse_bitmap_str(buf, ap_perms.apm, AP_DEVICES, newapm); 1163 if (rc) 1164 goto done; 1165 1166 rc = apmask_commit(newapm); 1167 1168 done: 1169 mutex_unlock(&ap_perms_mutex); 1170 if (rc) 1171 return rc; 1172 1173 ap_bus_revise_bindings(); 1174 1175 return count; 1176 } 1177 1178 static BUS_ATTR_RW(apmask); 1179 1180 static ssize_t aqmask_show(struct bus_type *bus, char *buf) 1181 { 1182 int rc; 1183 1184 if (mutex_lock_interruptible(&ap_perms_mutex)) 1185 return -ERESTARTSYS; 1186 rc = scnprintf(buf, PAGE_SIZE, 1187 "0x%016lx%016lx%016lx%016lx\n", 1188 ap_perms.aqm[0], ap_perms.aqm[1], 1189 ap_perms.aqm[2], ap_perms.aqm[3]); 1190 mutex_unlock(&ap_perms_mutex); 1191 1192 return rc; 1193 } 1194 > 1195 int __verify_queue_reservations(struct device_driver *drv, void *data) 1196 { 1197 int rc = 0; 1198 struct ap_driver *ap_drv = to_ap_drv(drv); 1199 unsigned long *newaqm = (unsigned long *)data; 1200 1201 /* 1202 * If the reserved bits do not identify queues reserved for use by the 1203 * non-default driver, there is no need to verify the driver is using 1204 * the queues. 1205 */ 1206 if (ap_drv->flags & AP_DRIVER_FLAG_DEFAULT) 1207 return 0; 1208 1209 /* The non-default driver's module must be loaded */ 1210 if (!try_module_get(drv->owner)) 1211 return 0; 1212 1213 if (ap_drv->in_use) 1214 if (ap_drv->in_use(ap_perms.apm, newaqm)) 1215 rc = -EADDRINUSE; 1216 1217 module_put(drv->owner); 1218 1219 return rc; 1220 } 1221 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org