tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/fpu head: fb58f76671de512da1ee76a77977eb6edb4d0071 commit: 0972ae347d728f65574452d8e0fa18ed7c68bfe5 [6/9] jump_label, x86: Introduce jump_entry_size() config: x86_64-randconfig-a003-20210309 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project cd9a69289c7825d54450cb6829fef2c8e0f1963a) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?... git remote add peterz-queue https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git git fetch --no-tags peterz-queue x86/fpu git checkout 0972ae347d728f65574452d8e0fa18ed7c68bfe5 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE)) { ^~~~~~~~~~~~~~~~~~~ JUMP_LABEL_NOP include/linux/jump_label.h:194:2: note: 'JUMP_LABEL_NOP' declared here JUMP_LABEL_NOP = 0, ^ arch/x86/kernel/jump_label.c:47:31: error: use of undeclared identifier 'init' addr, addr, addr, expect, init, type); ^ arch/x86/kernel/jump_label.c:76:5: error: use of undeclared identifier 'JUMP_LABEL_NOP_SIZE'; did you mean 'JUMP_LABEL_NOP'? JUMP_LABEL_NOP_SIZE); ^~~~~~~~~~~~~~~~~~~ JUMP_LABEL_NOP include/linux/jump_label.h:194:2: note: 'JUMP_LABEL_NOP' declared here JUMP_LABEL_NOP = 0, ^ arch/x86/kernel/jump_label.c:80:55: error: use of undeclared identifier 'JUMP_LABEL_NOP_SIZE'; did you mean 'JUMP_LABEL_NOP'? text_poke_bp((void *)jump_entry_code(entry), opcode, JUMP_LABEL_NOP_SIZE, NULL); ^~~~~~~~~~~~~~~~~~~ JUMP_LABEL_NOP include/linux/jump_label.h:194:2: note: 'JUMP_LABEL_NOP' declared here JUMP_LABEL_NOP = 0, ^ arch/x86/kernel/jump_label.c:114:12: error: use of undeclared identifier 'JUMP_LABEL_NOP_SIZE'; did you mean 'JUMP_LABEL_NOP'? opcode, JUMP_LABEL_NOP_SIZE, NULL); ^~~~~~~~~~~~~~~~~~~ JUMP_LABEL_NOP include/linux/jump_label.h:194:2: note: 'JUMP_LABEL_NOP' declared here JUMP_LABEL_NOP = 0, ^ 5 errors generated. vim +40 arch/x86/kernel/jump_label.c 0972ae347d728f Peter Zijlstra 2019-06-28 23 18cbc8bed0c707 Peter Zijlstra 2019-08-26 24 static const void * 86fa366b2e1b57 Peter Zijlstra 2021-03-10 25 __jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type) d9f5ab7b1c0a52 Jason Baron 2010-09-17 26 { 63f62addb88ec4 Peter Zijlstra 2019-10-03 27 const void *expect, *code; 63f62addb88ec4 Peter Zijlstra 2019-10-03 28 const void *addr, *dest; 9fc0f798ab8a6c Ard Biesheuvel 2018-09-18 29 63f62addb88ec4 Peter Zijlstra 2019-10-03 30 addr = (void *)jump_entry_code(entry); 63f62addb88ec4 Peter Zijlstra 2019-10-03 31 dest = (void *)jump_entry_target(entry); 18cbc8bed0c707 Peter Zijlstra 2019-08-26 32 63f62addb88ec4 Peter Zijlstra 2019-10-03 33 code = text_gen_insn(JMP32_INSN_OPCODE, addr, dest); d9f5ab7b1c0a52 Jason Baron 2010-09-17 34 8388f5d27cf18a Peter Zijlstra 2019-06-28 35 if (type == JUMP_LABEL_JMP) 8388f5d27cf18a Peter Zijlstra 2019-06-28 36 expect = x86_nops[5]; 8388f5d27cf18a Peter Zijlstra 2019-06-28 37 else 8388f5d27cf18a Peter Zijlstra 2019-06-28 38 expect = code; e71a5be15e47a7 Jeremy Fitzhardinge 2011-09-29 39 8388f5d27cf18a Peter Zijlstra 2019-06-28 @40 if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE)) { 8388f5d27cf18a Peter Zijlstra 2019-06-28 41 /* 8388f5d27cf18a Peter Zijlstra 2019-06-28 42 * The location is not an op that we were expecting. 8388f5d27cf18a Peter Zijlstra 2019-06-28 43 * Something went wrong. Crash the box, as something could be 8388f5d27cf18a Peter Zijlstra 2019-06-28 44 * corrupting the kernel. 8388f5d27cf18a Peter Zijlstra 2019-06-28 45 */ 8388f5d27cf18a Peter Zijlstra 2019-06-28 46 pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph != %5ph)) init:%d type:%d\n", 8388f5d27cf18a Peter Zijlstra 2019-06-28 47 addr, addr, addr, expect, init, type); 8388f5d27cf18a Peter Zijlstra 2019-06-28 48 BUG(); 8388f5d27cf18a Peter Zijlstra 2019-06-28 49 } 9fc0f798ab8a6c Ard Biesheuvel 2018-09-18 50 4cc6620b5e4c89 Daniel Bristot de Oliveira 2019-06-12 51 if (type == JUMP_LABEL_NOP) 86fa366b2e1b57 Peter Zijlstra 2021-03-10 52 code = x86_nops[5]; 18cbc8bed0c707 Peter Zijlstra 2019-08-26 53 63f62addb88ec4 Peter Zijlstra 2019-10-03 54 return code; 4cc6620b5e4c89 Daniel Bristot de Oliveira 2019-06-12 55 } 4cc6620b5e4c89 Daniel Bristot de Oliveira 2019-06-12 56 :::::: The code at line 40 was first introduced by commit :::::: 8388f5d27cf18ab67cb40c4ff289c5ab3f721369 jump_label, x86: Improve error when we fail expected text :::::: TO: Peter Zijlstra <peterz(a)infradead.org&gt; :::::: CC: Peter Zijlstra <peterz(a)infradead.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org