powerpc: add support for TIF_NOTIFY_SIGNAL

stable inclusion
from stable-v5.10.162
commit abab3d4444b5f4732d741f45feb954fabb78af7f
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6BTWC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.10.168&id=abab3d4444b5f4732d741f45feb954fabb78af7f

--------------------------------

[ Upstream commit 900f0713 ]

Wire up TIF_NOTIFY_SIGNAL handling for powerpc.

Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLi Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Reviewed-by: NWang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

arch/powerpc/include/asm/thread_info.h

@@ -99,6 +99,7 @@ void arch_setup_new_exec(void);
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
+#define TIF_NOTIFY_SIGNAL	3	/* signal notifications exist */
 #define TIF_SYSCALL_EMU		4	/* syscall emulation active */
 #define TIF_RESTORE_TM		5	/* need to restore TM FP/VEC/VSX */
 #define TIF_PATCH_PENDING	6	/* pending live patching update */
@@ -124,6 +125,7 @@ void arch_setup_new_exec(void);
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_32BIT		(1<<TIF_32BIT)
 #define _TIF_RESTORE_TM		(1<<TIF_RESTORE_TM)
@@ -145,7 +147,8 @@ void arch_setup_new_exec(void);
 
 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
-				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING)
+				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
+				 _TIF_NOTIFY_SIGNAL)
 #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
 
 /* Bits in local_flags */

arch/powerpc/kernel/signal.c

@@ -318,7 +318,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 	if (thread_info_flags & _TIF_PATCH_PENDING)
 		klp_update_patch_state(current);
 
-	if (thread_info_flags & _TIF_SIGPENDING) {
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
 		BUG_ON(regs != current->thread.regs);
 		do_signal(current);
 	}