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sx: fixup a braino in r334024

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If a thread waiting on sx dropped Giant it would not be properly
reacquired on exit from the routine, later resulting in panics
indicating Giant is not held (when it should be).

The bug was not present in the original patch sent to pho, I wittingly
added it just prior to the commit and only smoke-tested it.

Reported by:	pho
This commit is contained in:
Mateusz Guzik 2018-05-22 15:13:25 +00:00
parent f2b600b2bf
commit ee252fc995
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=334048
1 changed files with 1 additions and 1 deletions
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2
sys/kern/kern_sx.c
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@ -879,6 +879,7 @@ _sx_xlock_hard(struct sx *sx, uintptr_t x, int opts LOCK_FILE_LINE_ARG_DEF)
if (in_critical)
critical_exit();
#endif
GIANT_RESTORE();
#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING)
if (__predict_true(!doing_lockprof))
return (error);
@ -898,7 +899,6 @@ _sx_xlock_hard(struct sx *sx, uintptr_t x, int opts LOCK_FILE_LINE_ARG_DEF)
if (!error)
LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire, sx,
contested, waittime, file, line, LOCKSTAT_WRITER);
GIANT_RESTORE();
return (error);
}