include/linux/spinlock.h:378:9: sparse: sparse: context imbalance in 'gather_surplus_pages' - unexpected unlock

From: kernel test robot
Date: Thu Jun 25 2020 - 17:05:28 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 52366a107bf0600cf366f5ff3ea1f147b285e41f
commit: 9e953cda5cdf1c230a3c9b7fc4d5e94f15885a9b riscv: Introduce huge page support for 32/64bit kernel
date: 12 months ago
config: riscv-randconfig-s031-20200624 (attached as .config)
compiler: riscv32-linux-gcc (GCC) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.2-dirty
git checkout 9e953cda5cdf1c230a3c9b7fc4d5e94f15885a9b
# save the attached .config to linux build tree
make W=1 C=1 ARCH=riscv CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

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


sparse warnings: (new ones prefixed by >>)

>> include/linux/spinlock.h:378:9: sparse: sparse: context imbalance in 'gather_surplus_pages' - unexpected unlock
include/linux/spinlock.h:378:9: sparse: sparse: context imbalance in 'hugetlb_cow' - unexpected unlock
mm/hugetlb.c:4323:25: sparse: sparse: context imbalance in 'follow_hugetlb_page' - different lock contexts for basic block

vim +/gather_surplus_pages +378 include/linux/spinlock.h

c2f21ce2e31286a Thomas Gleixner 2009-12-02 375
3490565b633c705 Denys Vlasenko 2015-07-13 376 static __always_inline void spin_unlock(spinlock_t *lock)
c2f21ce2e31286a Thomas Gleixner 2009-12-02 377 {
c2f21ce2e31286a Thomas Gleixner 2009-12-02 @378 raw_spin_unlock(&lock->rlock);
c2f21ce2e31286a Thomas Gleixner 2009-12-02 379 }
c2f21ce2e31286a Thomas Gleixner 2009-12-02 380

:::::: The code at line 378 was first introduced by commit
:::::: c2f21ce2e31286a0a32f8da0a7856e9ca1122ef3 locking: Implement new raw_spinlock

:::::: TO: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
:::::: CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
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Attachment: .config.gz
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