entry: Snapshot thread flags

Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-3-mark.rutland@arm.com

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
index 0d7865a0731c..07c878d6e323 100644
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-kvm.h
@@ -75,7 +75,7 @@ static inline void xfer_to_guest_mode_prepare(void)
  */
 static inline bool __xfer_to_guest_mode_work_pending(void)
 {
-	unsigned long ti_work = READ_ONCE(current_thread_info()->flags);
+	unsigned long ti_work = read_thread_flags();
 
 	return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
 }