Hi Janosch, I love your patch! Perhaps something to improve: [auto build test WARNING on kvms390/next] [also build test WARNING on next-20220222] [cannot apply to kvm/master s390/features v5.17-rc5] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Janosch-Frank/kvm-s390-Add-PV-dump-support/20220223-172213 base: https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git next config: s390-randconfig-r044-20220223 (https://download.01.org/0day-ci/archive/20220224/202202240208.nprfvRMA-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e) 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-s390x-linux-gnu # https://github.com/0day-ci/linux/commit/63a2029ece7e8fee92aa5ad277e2cbd8b13b7e6b git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Janosch-Frank/kvm-s390-Add-PV-dump-support/20220223-172213 git checkout 63a2029ece7e8fee92aa5ad277e2cbd8b13b7e6b # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash arch/s390/kvm/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): In file included from arch/s390/kvm/pv.c:9: In file included from include/linux/kvm_host.h:41: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from arch/s390/kvm/pv.c:9: In file included from include/linux/kvm_host.h:41: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from arch/s390/kvm/pv.c:9: In file included from include/linux/kvm_host.h:41: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:501:33: 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:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: 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:617:20: 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:625:20: 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:634:21: 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:643:21: 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:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> arch/s390/kvm/pv.c:369:2: warning: variable 'cc' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!buff_kvm) ^~~~~~~~~~~~~~ include/linux/compiler.h:56:28: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/s390/kvm/pv.c:419:9: note: uninitialized use occurs here return cc ? -EINVAL : 0; ^~ arch/s390/kvm/pv.c:369:2: note: remove the 'if' if its condition is always false if (!buff_kvm) ^~~~~~~~~~~~~~ include/linux/compiler.h:56:23: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^ arch/s390/kvm/pv.c:357:2: warning: variable 'cc' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!buff_user_len || ^~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:28: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/s390/kvm/pv.c:419:9: note: uninitialized use occurs here return cc ? -EINVAL : 0; ^~ arch/s390/kvm/pv.c:357:2: note: remove the 'if' if its condition is always false if (!buff_user_len || ^~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:23: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^ arch/s390/kvm/pv.c:348:2: warning: variable 'cc' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (*gaddr & ~HPAGE_MASK) ^~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:28: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/s390/kvm/pv.c:419:9: note: uninitialized use occurs here return cc ? -EINVAL : 0; ^~ arch/s390/kvm/pv.c:348:2: note: remove the 'if' if its condition is always false if (*gaddr & ~HPAGE_MASK) ^~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:23: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^ arch/s390/kvm/pv.c:344:8: note: initialize the variable 'cc' to silence this warning int cc, ret; ^ = 0 15 warnings generated. vim +369 arch/s390/kvm/pv.c 309 310 /* 311 * kvm_s390_pv_dump_stor_state 312 * 313 * @kvm: pointer to the guest's KVM struct 314 * @buff_user: Userspace pointer where we will write the results to 315 * @gaddr: Starting absolute guest address for which the storage state 316 * is requested. This value will be updated with the last 317 * address for which data was written when returning to 318 * userspace. 319 * @buff_user_len: Length of the buff_user buffer 320 * @rc: Pointer to where the uvcb return code is stored 321 * @rrc: Pointer to where the uvcb return reason code is stored 322 * 323 * Return: 324 * 0 on success 325 * -ENOMEM if allocating the cache fails 326 * -EINVAL if gaddr is not aligned to 1MB 327 * -EINVAL if buff_user_len is not aligned to uv_info.conf_dump_storage_state_len 328 * -EINVAL if the UV call fails, rc and rrc will be set in this case 329 * -EFAULT if copying the result to buff_user failed 330 */ 331 int kvm_s390_pv_dump_stor_state(struct kvm *kvm, void __user *buff_user, 332 u64 *gaddr, u64 buff_user_len, u16 *rc, u16 *rrc) 333 { 334 struct uv_cb_dump_stor_state uvcb = { 335 .header.cmd = UVC_CMD_DUMP_CONF_STOR_STATE, 336 .header.len = sizeof(uvcb), 337 .config_handle = kvm->arch.pv.handle, 338 .gaddr = *gaddr, 339 .dump_area_origin = 0, 340 }; 341 size_t buff_kvm_size; 342 size_t size_done = 0; 343 u8 *buff_kvm = NULL; 344 int cc, ret; 345 346 ret = -EINVAL; 347 /* UV call processes 1MB guest storage chunks at a time */ 348 if (*gaddr & ~HPAGE_MASK) 349 goto out; 350 351 /* 352 * We provide the storage state for 1MB chunks of guest 353 * storage. The buffer will need to be aligned to 354 * conf_dump_storage_state_len so we don't end on a partial 355 * chunk. 356 */ 357 if (!buff_user_len || 358 buff_user_len & (uv_info.conf_dump_storage_state_len - 1)) 359 goto out; 360 361 /* 362 * Allocate a buffer from which we will later copy to the user process. 363 * 364 * We don't want userspace to dictate our buffer size so we limit it to DUMP_BUFF_LEN. 365 */ 366 ret = -ENOMEM; 367 buff_kvm_size = buff_user_len <= DUMP_BUFF_LEN ? buff_user_len : DUMP_BUFF_LEN; 368 buff_kvm = vzalloc(buff_kvm_size); > 369 if (!buff_kvm) --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
