Re: [PATCH 4/4] signals/sigaltstack: Change SS_AUTODISARM to (1U << 31)

Using bit 4 divides the space of available bits strangely.  Use bit
31 instead so that we have a better chance of keeping flag and mode
bits separate in the long run.

Cc: Stas Sergeev <redacted>
Cc: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
Cc: Aleksa Sarai <cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
Cc: Amanieu d'Antras <redacted>
Cc: Andrea Arcangeli <redacted>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Andy Lutomirski <redacted>
Cc: Borislav Petkov <redacted>
Cc: Brian Gerst <redacted>
Cc: Denys Vlasenko <redacted>
Cc: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Frederic Weisbecker <redacted>
Cc: H. Peter Anvin <redacted>
Cc: Heinrich Schuchardt <redacted>
Cc: Jason Low <redacted>
Cc: Josh Triplett <redacted>
Cc: Konstantin Khlebnikov <redacted>
Cc: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Oleg Nesterov <redacted>
Cc: Palmer Dabbelt <redacted>
Cc: Paul Moore <redacted>
Cc: Pavel Emelyanov <redacted>
Cc: Peter Zijlstra <redacted>
Cc: Richard Weinberger <richard-/L3Ra7n9ekc@public.gmane.org>
Cc: Sasha Levin <redacted>
Cc: Shuah Khan <redacted>
Cc: Tejun Heo <redacted>
Cc: Thomas Gleixner <redacted>
Cc: Vladimir Davydov <redacted>
Cc: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Andy Lutomirski <redacted>
---
  include/uapi/linux/signal.h               | 2 +-
  tools/testing/selftests/sigaltstack/sas.c | 2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/signal.h b/include/uapi/linux/signal.h
index 738826048af2..cd0804b6bfa2 100644
--- a/include/uapi/linux/signal.h
+++ b/include/uapi/linux/signal.h

@@ -8,7 +8,7 @@
  #define SS_DISABLE	2
  
  /* bit-flags */
-#define SS_AUTODISARM	(1 << 4)	/* disable sas during sighandling */
+#define SS_AUTODISARM	(1U << 31)	/* disable sas during sighandling */