Hi "Matthew, Thank you for the patch! Yet something to improve: [auto build test ERROR on tip/x86/core] [also build test ERROR on arm64/for-next/core powerpc/next s390/features linus/master v5.16-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/Matthew-Wilcox-Oracle/Convert-vm... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git e463a09af2f0677b9485a7e8e4e70b396b2ffb6f config: riscv-randconfig-r012-20211213 (https://download.01.org/0day-ci/archive/20211213/202112131020.pSJ77Cjj-lk...) compiler: riscv64-linux-gcc (GCC) 11.2.0 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://github.com/0day-ci/linux/commit/e1684ad72e2cce57ac90ae1270668753f... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Matthew-Wilcox-Oracle/Convert-vmcore-to-use-an-iov_iter/20211213-080748 git checkout e1684ad72e2cce57ac90ae1270668753f1aa6c60 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/kernel/ fs/proc/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): arch/riscv/kernel/crash_dump.c: In function 'copy_oldmem_page': 35 | csize = copy_to_iter(vaddr + offset, csize, iter); | ^~~~~~~~~~~~ | copy_to_user cc1: some warnings being treated as errors -- fs/proc/vmcore.c:135:9: warning: no previous prototype for 'read_from_oldmem_iter' [-Wmissing-prototypes] 135 | ssize_t read_from_oldmem_iter(struct iov_iter *iter, size_t count, | ^~~~~~~~~~~~~~~~~~~~~ fs/proc/vmcore.c: In function 'read_from_oldmem_iter': 157 | tmp = iov_iter_zero(nr_bytes, iter); | ^~~~~~~~~~~~~ fs/proc/vmcore.c: In function 'read_from_oldmem': 187 | struct iov_iter iter; | ^~~~ fs/proc/vmcore.c:188:22: error: storage size of 'iov' isn't known 188 | struct iovec iov; | ^~~ 189 | struct kvec kvec; | ^~~~ fs/proc/vmcore.c:194:17: error: implicit declaration of function 'iov_iter_init'; did you mean 'klist_iter_init'? [-Werror=implicit-function-declaration] 194 | iov_iter_init(&iter, READ, &iov, 1, count); | ^~~~~~~~~~~~~ | klist_iter_init 198 | iov_iter_kvec(&iter, READ, &kvec, 1, count); | ^~~~~~~~~~~~~ fs/proc/vmcore.c:189:21: warning: unused variable 'kvec' [-Wunused-variable] 189 | struct kvec kvec; | ^~~~ fs/proc/vmcore.c:188:22: warning: unused variable 'iov' [-Wunused-variable] 188 | struct iovec iov; | ^~~ fs/proc/vmcore.c:187:25: warning: unused variable 'iter' [-Wunused-variable] 187 | struct iov_iter iter; | ^~~~ fs/proc/vmcore.c:202:1: error: control reaches end of non-void function [-Werror=return-type] 202 | } | ^ cc1: some warnings being treated as errors vim +35 arch/riscv/kernel/crash_dump.c 10 11 /** 12 * copy_oldmem_page() - copy one page from old kernel memory 13 * @pfn: page frame number to be copied 14 * @buf: buffer where the copied page is placed 15 * @csize: number of bytes to copy 16 * @offset: offset in bytes into the page 17 * @userbuf: if set, @buf is in a user address space 18 * 19 * This function copies one page from old kernel memory into buffer pointed by 20 * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes 21 * copied or negative error in case of failure. 22 */ 23 ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, 24 size_t csize, unsigned long offset) 25 { 26 void *vaddr; 27 28 if (!csize) 29 return 0; 30 31 vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB); 32 if (!vaddr) 33 return -ENOMEM; 34 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org