[PATCH] riscv: add support for TIF_NOTIFY_SIGNAL

[Jens Axboe]

Wire up TIF_NOTIFY_SIGNAL handling for riscv.

Cc: linux-riscv at lists.infradead.org
Signed-off-by: Jens Axboe <axboe at 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/riscv/include/asm/thread_info.h | 5 ++++-
 arch/riscv/kernel/signal.c           | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index a390711129de..97bf5a1575d2 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -74,6 +74,7 @@ struct thread_info {
 #define TIF_SYSCALL_TRACEPOINT  6       /* syscall tracepoint instrumentation */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing */
 #define TIF_SECCOMP		8	/* syscall secure computing */
+#define TIF_NOTIFY_SIGNAL	9	/* signal notifications exist */
 
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
@@ -82,9 +83,11 @@ struct thread_info {
 #define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
 
 #define _TIF_WORK_MASK \
-	(_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED)
+	(_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+	 _TIF_NOTIFY_SIGNAL)
 
 #define _TIF_SYSCALL_WORK \
 	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT | \
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index bc6841867b51..469aef8ed922 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -310,7 +310,7 @@ asmlinkage __visible void do_notify_resume(struct pt_regs *regs,
 					   unsigned long thread_info_flags)
 {
 	/* Handle pending signal delivery */
-	if (thread_info_flags & _TIF_SIGPENDING)
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
 		do_signal(regs);
 
 	if (thread_info_flags & _TIF_NOTIFY_RESUME)
-- 
2.29.0

-- 
Jens Axboe