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/20220224/202202240337.wksMLgVn-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/8e5a2c1d95d561cf1530c7a3427a1a367ab67364 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 8e5a2c1d95d561cf1530c7a3427a1a367ab67364 # 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/kvm-s390.c:23: 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/kvm-s390.c:23: 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/kvm-s390.c:23: 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/kvm-s390.c:5088:5: warning: no previous prototype for function 'kvm_s390_handle_pv_vcpu_dump' [-Wmissing-prototypes] int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu, struct kvm_pv_cmd *cmd) ^ arch/s390/kvm/kvm-s390.c:5088:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu, struct kvm_pv_cmd *cmd) ^ static 13 warnings generated. vim +/kvm_s390_handle_pv_vcpu_dump +5088 arch/s390/kvm/kvm-s390.c 5087 > 5088 int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu, struct kvm_pv_cmd *cmd) 5089 { 5090 struct kvm_s390_pv_dmp dmp; 5091 void *data; 5092 int ret; 5093 5094 /* Dump initialization is a prerequisite */ 5095 if (!vcpu->kvm->arch.pv.dumping) 5096 return -EINVAL; 5097 5098 if (copy_from_user(&dmp, (__u8 __user *)cmd->data, sizeof(dmp))) 5099 return -EFAULT; 5100 5101 /* We only handle this subcmd right now */ 5102 if (dmp.subcmd != KVM_PV_DUMP_CPU) 5103 return -EINVAL; 5104 5105 /* CPU dump length is the same as create cpu storage donation. */ 5106 if (dmp.buff_len != uv_info.guest_cpu_stor_len) 5107 return -EINVAL; 5108 5109 data = vzalloc(uv_info.guest_cpu_stor_len); 5110 if (!data) 5111 return -ENOMEM; 5112 5113 ret = kvm_s390_pv_dump_cpu(vcpu, data, &cmd->rc, &cmd->rrc); 5114 5115 VCPU_EVENT(vcpu, 3, "PROTVIRT DUMP CPU %d rc %x rrc %x", 5116 vcpu->vcpu_id, cmd->rc, cmd->rrc); 5117 5118 if (ret) { 5119 vfree(data); 5120 return -EINVAL; 5121 } 5122 5123 /* On success copy over the dump data */ 5124 if (copy_to_user((__u8 __user *)dmp.buff_addr, data, uv_info.guest_cpu_stor_len)) { 5125 vfree(data); 5126 return -EFAULT; 5127 } 5128 5129 vfree(data); 5130 return 0; 5131 } 5132 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx