arch/arc/include/asm/atomic.h:118:9: sparse: sparse: context imbalance in 'dm_exception_table_unlock' - unexpected unlock

arch/arc/include/asm/atomic.h:118:9: sparse: sparse: context imbalance in 'dm_exception_table_unlock' - unexpected unlock

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Nicholas Piggin <npiggin@gmail.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
CC: Thomas Gleixner <tglx@linutronix.de>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   c2dc4c073fb71b50904493657a7622b481b346e3
commit: 044d0d6de9f50192f9697583504a382347ee95ca lockdep: Only trace IRQ edges
date:   10 weeks ago
:::::: branch date: 7 hours ago
:::::: commit date: 10 weeks ago
config: arc-randconfig-s031-20201101 (attached as .config)
compiler: arceb-elf-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: v0.6.3-68-g49c98aa3-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=044d0d6de9f50192f9697583504a382347ee95ca
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 044d0d6de9f50192f9697583504a382347ee95ca
        # 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=arc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


"sparse warnings: (new ones prefixed by >>)"
   drivers/md/dm-snap.c: note: in included file (through include/linux/mm.h, include/linux/bvec.h, include/linux/blk_types.h, ...):
   include/linux/bit_spinlock.h:35:9: sparse: sparse: context imbalance in 'dm_exception_table_lock' - wrong count at exit
   drivers/md/dm-snap.c: note: in included file (through include/linux/atomic.h, include/asm-generic/bitops/lock.h, arch/arc/include/asm/bitops.h, ...):
>> arch/arc/include/asm/atomic.h:118:9: sparse: sparse: context imbalance in 'dm_exception_table_unlock' - unexpected unlock

vim +/dm_exception_table_unlock +118 arch/arc/include/asm/atomic.h

14e968bad788de Vineet Gupta   2013-01-18  102  
14e968bad788de Vineet Gupta   2013-01-18  103  static inline void atomic_set(atomic_t *v, int i)
14e968bad788de Vineet Gupta   2013-01-18  104  {
14e968bad788de Vineet Gupta   2013-01-18  105  	/*
14e968bad788de Vineet Gupta   2013-01-18  106  	 * Independent of hardware support, all of the atomic_xxx() APIs need
14e968bad788de Vineet Gupta   2013-01-18  107  	 * to follow the same locking rules to make sure that a "hardware"
14e968bad788de Vineet Gupta   2013-01-18  108  	 * atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn
14e968bad788de Vineet Gupta   2013-01-18  109  	 * sequence
14e968bad788de Vineet Gupta   2013-01-18  110  	 *
14e968bad788de Vineet Gupta   2013-01-18  111  	 * Thus atomic_set() despite being 1 insn (and seemingly atomic)
14e968bad788de Vineet Gupta   2013-01-18  112  	 * requires the locking.
14e968bad788de Vineet Gupta   2013-01-18  113  	 */
14e968bad788de Vineet Gupta   2013-01-18  114  	unsigned long flags;
14e968bad788de Vineet Gupta   2013-01-18  115  
14e968bad788de Vineet Gupta   2013-01-18  116  	atomic_ops_lock(flags);
62e8a3258bda11 Peter Zijlstra 2015-09-18  117  	WRITE_ONCE(v->counter, i);
14e968bad788de Vineet Gupta   2013-01-18 @118  	atomic_ops_unlock(flags);
14e968bad788de Vineet Gupta   2013-01-18  119  }
f7d11e93ee97a3 Peter Zijlstra 2014-03-23  120  

:::::: The code at line 118 was first introduced by commit
:::::: 14e968bad788de922a755a84b92cb29f8c1342e4 ARC: Atomic/bitops/cmpxchg/barriers

:::::: TO: Vineet Gupta <vgupta@synopsys.com>
:::::: CC: Vineet Gupta <vgupta@synopsys.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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