[PATCH] ia64: add support for TIF_NOTIFY_SIGNAL

[Jens Axboe <axboe@kernel.dk>]

Wire up TIF_NOTIFY_SIGNAL handling for ia64.

Cc: linux-ia64@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

5.11 has support queued up for TIF_NOTIFY_SIGNAL, see this posting
for details:

https://lore.kernel.org/io-uring/20201026203230.386348-1-axboe@kernel.dk/

As part of that work, I'm adding TIF_NOTIFY_SIGNAL support to all archs,
as that will enable a set of cleanups once all of them support it. I'm
happy carrying this patch if need be, or it can be funelled through the
arch tree. Let me know.

 arch/ia64/include/asm/thread_info.h | 4 +++-
 arch/ia64/kernel/process.c          | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index 64a1011f6812..759d7d68a5f2 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -104,6 +104,7 @@ struct thread_info {
 #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
 #define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
 #define TIF_NOTIFY_RESUME	6	/* resumption notification requested */
+#define TIF_NOTIFY_SIGNAL	7	/* signal notification exist */
 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
 #define TIF_MCA_INIT		18	/* this task is processing MCA or INIT */
 #define TIF_DB_DISABLED		19	/* debug trap disabled for fsyscall */
@@ -115,6 +116,7 @@ struct thread_info {
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
 #define _TIF_SYSCALL_TRACEAUDIT	(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_SIGNAL_NOTIFY	(1 << TIF_SIGNAL_NOTIFY)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_MCA_INIT		(1 << TIF_MCA_INIT)
@@ -124,7 +126,7 @@ struct thread_info {
 
 /* "work to do on user-return" bits */
 #define TIF_ALLWORK_MASK	(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\
-				 _TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE)
+				 _TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_NOTIFY_SIGNAL)
 /* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
 #define TIF_WORK_MASK		(TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
 
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 6b61a703bcf5..0e0146daa88d 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -171,7 +171,8 @@ do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
 	}
 
 	/* deal with pending signal delivery */
-	if (test_thread_flag(TIF_SIGPENDING)) {
+	if (test_thread_flag(TIF_SIGPENDING) ||
+	    test_thread_flags(TIF_NOTIFY_SIGNAL)) {
 		local_irq_enable();	/* force interrupt enable */
 		ia64_do_signal(scr, in_syscall);
 	}
-- 
2.29.0

-- 
Jens Axboe