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 <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: https://lore.kernel.org/r/20211129130653.2037928-9-mark.rutland@arm.com
This commit is contained in:
Mark Rutland 2021-11-29 13:06:50 +00:00 committed by Thomas Gleixner
parent e538c58491
commit 4ea7ce0a79

View File

@ -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;
}