tree: https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/fault head: eefc5d2176680683703cf4c056949054da2d5f53 commit: a5ff54330bd58fa9d5dba5c9b44aabb51af592aa [7/13] x86/fault: Improve kernel-executing-user-memory handling config: x86_64-randconfig-r003-20210209 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/commit/?id... git remote add luto https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git git fetch --no-tags luto x86/fault git checkout a5ff54330bd58fa9d5dba5c9b44aabb51af592aa # save the attached .config to linux build tree make W=1 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 >>): In file included from include/linux/kernel.h:16, from arch/x86/include/asm/percpu.h:27, from arch/x86/include/asm/current.h:6, from include/linux/sched.h:12, from arch/x86/mm/fault.c:7: arch/x86/mm/fault.c: In function 'is_errata93': 461 | printk_once(errata93_warning); | ^~~~~~~~~~~~~~~~ include/linux/printk.h:445:10: note: in definition of macro 'printk_once' 445 | printk(fmt, ##__VA_ARGS__); \ | ^~~ arch/x86/mm/fault.c:461:15: note: each undeclared identifier is reported only once for each function it appears in 461 | printk_once(errata93_warning); | ^~~~~~~~~~~~~~~~ include/linux/printk.h:445:10: note: in definition of macro 'printk_once' 445 | printk(fmt, ##__VA_ARGS__); \ | ^~~ vim +/errata93_warning +461 arch/x86/mm/fault.c ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 428 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 429 /* 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 430 * Workaround for K8 erratum #93 & buggy BIOS. 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 431 * 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 432 * BIOS SMM functions are required to use a specific workaround 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 433 * to avoid corruption of the 64bit RIP register on C stepping K8. 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 434 * 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 435 * A lot of BIOS that didn't get tested properly miss this. 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 436 * 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 437 * The OS sees this as a page fault with the upper 32bits of RIP cleared. 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 438 * Try to work around it here. 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 439 * 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 440 * Note we only handle faults in kernel here. 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 441 * Does nothing on 32-bit. fdfe8aa84dd78c arch/x86/mm/fault_64.c Harvey Harrison 2008-01-30 442 */ ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 443 static int is_errata93(struct pt_regs *regs, unsigned long address) ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 444 { a5ff54330bd58f arch/x86/mm/fault.c Andy Lutomirski 2021-02-09 445 #if defined(CONFIG_X86_64) a5ff54330bd58f arch/x86/mm/fault.c Andy Lutomirski 2021-02-09 446 if (!is_amd_k8_pre_npt()) a5ff54330bd58f arch/x86/mm/fault.c Andy Lutomirski 2021-02-09 447 return 0; a5ff54330bd58f arch/x86/mm/fault.c Andy Lutomirski 2021-02-09 448 a5ff54330bd58f arch/x86/mm/fault.c Andy Lutomirski 2021-02-09 449 if (user_mode(regs)) e05139f2569ecf arch/x86/mm/fault.c Jan Beulich 2011-09-28 450 return 0; e05139f2569ecf arch/x86/mm/fault.c Jan Beulich 2011-09-28 451 65ea5b03499035 arch/x86/mm/fault_64.c H. Peter Anvin 2008-01-30 452 if (address != regs->ip) ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 453 return 0; 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 454 ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 455 if ((address >> 32) != 0) ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 456 return 0; 2d4a71676f4d89 arch/x86/mm/fault.c Ingo Molnar 2009-02-20 457 ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 458 address |= 0xffffffffUL << 32; ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 459 if ((address >= (u64)_stext && address <= (u64)_etext) || ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 460 (address >= MODULES_VADDR && address <= MODULES_END)) { a454ab3110175d arch/x86/mm/fault.c Ingo Molnar 2009-05-03 @461 printk_once(errata93_warning); 65ea5b03499035 arch/x86/mm/fault_64.c H. Peter Anvin 2008-01-30 462 regs->ip = address; ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 463 return 1; ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 464 } fdfe8aa84dd78c arch/x86/mm/fault_64.c Harvey Harrison 2008-01-30 465 #endif ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 466 return 0; ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 467 } ^1da177e4c3f41 arch/x86_64/mm/fault.c Linus Torvalds 2005-04-16 468 :::::: The code at line 461 was first introduced by commit :::::: a454ab3110175d710f4f9a96226a26ce4d5d5de2 x86, mm: fault.c, use printk_once() in is_errata93() :::::: TO: Ingo Molnar <mingo(a)elte.hu&gt; :::::: CC: Ingo Molnar <mingo(a)elte.hu&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org