tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 06a4ec1d9dc652e17ee3ac2ceb6c7cf6c2b75cdd commit: 19d0070a2792181f79df01277fe00b83b9f7eda7 timekeeping/vsyscall: Provide vdso_update_begin/end() date: 13 days ago config: arm64-randconfig-s031-20200818 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.2-183-gaa6ede3b-dirty git checkout 19d0070a2792181f79df01277fe00b83b9f7eda7 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) kernel/time/vsyscall.c: note: in included file: kernel/time/vsyscall.c:163:6: sparse: sparse: context imbalance in 'vdso_update_end' - unexpected unlock # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 19d0070a2792181f79df01277fe00b83b9f7eda7 vim +/vdso_update_begin +37 include/vdso/helpers.h 00b26474c2f161 Vincenzo Frascino 2019-06-21 29 00b26474c2f161 Vincenzo Frascino 2019-06-21 30 static __always_inline void vdso_write_begin(struct vdso_data *vd) 00b26474c2f161 Vincenzo Frascino 2019-06-21 31 { 00b26474c2f161 Vincenzo Frascino 2019-06-21 32 /* 00b26474c2f161 Vincenzo Frascino 2019-06-21 33 * WRITE_ONCE it is required otherwise the compiler can validly tear 00b26474c2f161 Vincenzo Frascino 2019-06-21 34 * updates to vd[x].seq and it is possible that the value seen by the 00b26474c2f161 Vincenzo Frascino 2019-06-21 35 * reader it is inconsistent. 00b26474c2f161 Vincenzo Frascino 2019-06-21 36 */ 00b26474c2f161 Vincenzo Frascino 2019-06-21 @37 WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1); 00b26474c2f161 Vincenzo Frascino 2019-06-21 38 WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1); 00b26474c2f161 Vincenzo Frascino 2019-06-21 39 smp_wmb(); 00b26474c2f161 Vincenzo Frascino 2019-06-21 40 } 00b26474c2f161 Vincenzo Frascino 2019-06-21 41 :::::: The code at line 37 was first introduced by commit :::::: 00b26474c2f1613d7ab894c525f775c67c8a9e8f lib/vdso: Provide generic VDSO implementation :::::: TO: Vincenzo Frascino <vincenzo.frascino(a)arm.com&gt; :::::: CC: Thomas Gleixner <tglx(a)linutronix.de&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org