Hi Vincenzo, FYI, the error/warning still remains. tree: https://github.com/intel/linux-intel-lts.git 4.19/android_r head: 8367d521b6ca9b77d18fbb56f936df6824f0843c commit: 0854e59101a9219eb1607fb584dde8da4dea220e [16666/25353] UPSTREAM: lib/vdso: Build 32 bit specific functions in the right context config: mips-buildonly-randconfig-r005-20211122 (attached as .config) compiler: mipsel-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/intel/linux-intel-lts/commit/0854e59101a9219eb1607fb58... git remote add intel-lts https://github.com/intel/linux-intel-lts.git git fetch --no-tags intel-lts 4.19/android_r git checkout 0854e59101a9219eb1607fb584dde8da4dea220e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=mips 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 lib/vdso/gettimeofday.c:26, from <command-line>: arch/mips/include/asm/vdso/gettimeofday.h: In function 'clock_gettime_fallback': arch/mips/include/asm/vdso/gettimeofday.h:59:38: error: '__NR_clock_gettime64' undeclared (first use in this function) 59 | register long nr asm("v0") = __NR_clock_gettime64; | ^~~~~~~~~~~~~~~~~~~~ arch/mips/include/asm/vdso/gettimeofday.h:59:38: note: each undeclared identifier is reported only once for each function it appears in arch/mips/include/asm/vdso/gettimeofday.h: In function 'clock_getres_fallback': arch/mips/include/asm/vdso/gettimeofday.h:83:38: error: '__NR_clock_getres_time64' undeclared (first use in this function) 83 | register long nr asm("v0") = __NR_clock_getres_time64; | ^~~~~~~~~~~~~~~~~~~~~~~~ arch/mips/vdso/vgettimeofday.c: At top level: arch/mips/vdso/vgettimeofday.c:14:5: warning: no previous prototype for '__vdso_clock_gettime' [-Wmissing-prototypes] 14 | int __vdso_clock_gettime(clockid_t clock, | ^~~~~~~~~~~~~~~~~~~~ arch/mips/vdso/vgettimeofday.c: In function '__vdso_clock_gettime': 17 | return __cvdso_clock_gettime32(clock, ts); | ^~~~~~~~~~~~~~~~~~~~~~~ | __cvdso_clock_gettime arch/mips/vdso/vgettimeofday.c: At top level: arch/mips/vdso/vgettimeofday.c:28:5: warning: no previous prototype for '__vdso_gettimeofday' [-Wmissing-prototypes] 28 | int __vdso_gettimeofday(struct __kernel_old_timeval *tv, | ^~~~~~~~~~~~~~~~~~~ arch/mips/vdso/vgettimeofday.c:36:5: warning: no previous prototype for '__vdso_clock_getres' [-Wmissing-prototypes] 36 | int __vdso_clock_getres(clockid_t clock_id, | ^~~~~~~~~~~~~~~~~~~ arch/mips/vdso/vgettimeofday.c: In function '__vdso_clock_getres': 39 | return __cvdso_clock_getres_time32(clock_id, res); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ | __cvdso_clock_getres_common arch/mips/vdso/vgettimeofday.c: At top level: arch/mips/vdso/vgettimeofday.c:42:5: warning: no previous prototype for '__vdso_clock_gettime64' [-Wmissing-prototypes] 42 | int __vdso_clock_gettime64(clockid_t clock, | ^~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +17 arch/mips/vdso/vgettimeofday.c 6b7f832e465d88 Vincenzo Frascino 2019-06-21 12 6b7f832e465d88 Vincenzo Frascino 2019-06-21 13 #if _MIPS_SIM != _MIPS_SIM_ABI64 6b7f832e465d88 Vincenzo Frascino 2019-06-21 14 int __vdso_clock_gettime(clockid_t clock, 6b7f832e465d88 Vincenzo Frascino 2019-06-21 15 struct old_timespec32 *ts) 6b7f832e465d88 Vincenzo Frascino 2019-06-21 16 { 6b7f832e465d88 Vincenzo Frascino 2019-06-21 @17 return __cvdso_clock_gettime32(clock, ts); 6b7f832e465d88 Vincenzo Frascino 2019-06-21 18 } 6b7f832e465d88 Vincenzo Frascino 2019-06-21 19 cf84512fe7aac9 Vincenzo Frascino 2019-11-29 20 #ifdef CONFIG_MIPS_CLOCK_VSYSCALL cf84512fe7aac9 Vincenzo Frascino 2019-11-29 21 cf84512fe7aac9 Vincenzo Frascino 2019-11-29 22 /* cf84512fe7aac9 Vincenzo Frascino 2019-11-29 23 * This is behind the ifdef so that we don't provide the symbol when there's no cf84512fe7aac9 Vincenzo Frascino 2019-11-29 24 * possibility of there being a usable clocksource, because there's nothing we cf84512fe7aac9 Vincenzo Frascino 2019-11-29 25 * can do without it. When libc fails the symbol lookup it should fall back on cf84512fe7aac9 Vincenzo Frascino 2019-11-29 26 * the standard syscall path. cf84512fe7aac9 Vincenzo Frascino 2019-11-29 27 */ 6b7f832e465d88 Vincenzo Frascino 2019-06-21 28 int __vdso_gettimeofday(struct __kernel_old_timeval *tv, 6b7f832e465d88 Vincenzo Frascino 2019-06-21 29 struct timezone *tz) 6b7f832e465d88 Vincenzo Frascino 2019-06-21 30 { 6b7f832e465d88 Vincenzo Frascino 2019-06-21 31 return __cvdso_gettimeofday(tv, tz); 6b7f832e465d88 Vincenzo Frascino 2019-06-21 32 } 6b7f832e465d88 Vincenzo Frascino 2019-06-21 33 cf84512fe7aac9 Vincenzo Frascino 2019-11-29 34 #endif /* CONFIG_MIPS_CLOCK_VSYSCALL */ cf84512fe7aac9 Vincenzo Frascino 2019-11-29 35 23dea1cf7ed384 Vincenzo Frascino 2019-06-21 36 int __vdso_clock_getres(clockid_t clock_id, 23dea1cf7ed384 Vincenzo Frascino 2019-06-21 37 struct old_timespec32 *res) 23dea1cf7ed384 Vincenzo Frascino 2019-06-21 38 { 23dea1cf7ed384 Vincenzo Frascino 2019-06-21 @39 return __cvdso_clock_getres_time32(clock_id, res); 23dea1cf7ed384 Vincenzo Frascino 2019-06-21 40 } 23dea1cf7ed384 Vincenzo Frascino 2019-06-21 41 :::::: The code at line 17 was first introduced by commit :::::: 6b7f832e465d88fca5f3a07b85e664f962c88e0b BACKPORT: mips: Add support for generic vDSO :::::: TO: Vincenzo Frascino <vincenzo.frascino(a)arm.com&gt; :::::: CC: Alistair Delva <adelva(a)google.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org