openrisc: 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 <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Stafford Horne <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Stefan Kristiansson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c
index 99516c9191c78408dab5846ced21108dc05b7c24..92c5b70740f53821acbcd3b0c173d1711690bf59 100644 (file)
--- a/arch/openrisc/kernel/signal.c
+++ b/arch/openrisc/kernel/signal.c
@@ -313,7 +313,7 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
                        }
                }
                local_irq_disable();
-               thread_flags = current_thread_info()->flags;
+               thread_flags = read_thread_flags();
        } while (thread_flags & _TIF_WORK_MASK);
        return 0;
 }