[PATCH v4 03/27] x86/entry: Flip _TIF_SIGPENDING and _TIF_NOTIFY_RESUME handling

[Peter Zijlstra]

Make sure we run task_work before we hit any kind of userspace -- very
much including signals.

Suggested-by: Andy Lutomirski <luto@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/x86/entry/common.c                   |    8 
 usr/src/linux-2.6/arch/x86/entry/common.c |  440 ------------------------------
 2 files changed, 4 insertions(+), 444 deletions(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -155,16 +155,16 @@ static void exit_to_usermode_loop(struct
 		if (cached_flags & _TIF_PATCH_PENDING)
 			klp_update_patch_state(current);
 
-		/* deal with pending signal delivery */
-		if (cached_flags & _TIF_SIGPENDING)
-			do_signal(regs);
-
 		if (cached_flags & _TIF_NOTIFY_RESUME) {
 			clear_thread_flag(TIF_NOTIFY_RESUME);
 			tracehook_notify_resume(regs);
 			rseq_handle_notify_resume(NULL, regs);
 		}
 
+		/* deal with pending signal delivery */
+		if (cached_flags & _TIF_SIGPENDING)
+			do_signal(regs);
+
 		if (cached_flags & _TIF_USER_RETURN_NOTIFY)
 			fire_user_return_notifiers();