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lockdep: Fix preemption WARN for spurious IRQ-enable

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It is valid (albeit uncommon) to call local_irq_enable() without first
having called local_irq_disable(). In this case we enter
lockdep_hardirqs_on*() with IRQs enabled and trip a preemption warning
for using __this_cpu_read().

Use this_cpu_read() instead to avoid the warning.

Fixes: 4d004099a6 ("lockdep: Fix lockdep recursion")
Reported-by: syzbot+53f8ce8bbc07924b6417@syzkaller.appspotmail.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
Peter Zijlstra 2020-10-22 12:23:02 +02:00
parent ed3e453798
commit f8e48a3dca
1 changed files with 2 additions and 2 deletions
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4
kernel/locking/lockdep.c
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@ -4057,7 +4057,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip)
if (unlikely(in_nmi()))
return;
if (unlikely(__this_cpu_read(lockdep_recursion)))
if (unlikely(this_cpu_read(lockdep_recursion)))
return;
if (unlikely(lockdep_hardirqs_enabled())) {
@ -4126,7 +4126,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip)
goto skip_checks;
}
if (unlikely(__this_cpu_read(lockdep_recursion)))
if (unlikely(this_cpu_read(lockdep_recursion)))
return;
if (lockdep_hardirqs_enabled()) {