The following commit has been merged into the locking/urgent branch of tip: Commit-ID: f8e48a3dca060e80f672d398d181db1298fbc86c Gitweb: https://git.kernel.org/tip/f8e48a3dca060e80f672d398d181db1298fbc86c Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Thu, 22 Oct 2020 12:23:02 +02:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Thu, 22 Oct 2020 12:37:22 +02:00 lockdep: Fix preemption WARN for spurious IRQ-enable 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@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> --- kernel/locking/lockdep.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 3e99dfe..fc206ae 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -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()) {
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