[RFC PATCH 04/10] alpha: snapshot thread flags

From: Mark Rutland
Date: Wed Jun 09 2021 - 08:20:32 EST

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, we should snapshot the flags prior to using them.
Let's use the new helpers to do so on alpha.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
arch/alpha/kernel/signal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index 948b89789da8..b1b7623ea67e 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -535,6 +535,6 @@ do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
- thread_flags = current_thread_info()->flags;
+ thread_flags = read_thread_flags();
} while (thread_flags & _TIF_WORK_MASK);