The support for user return notifier infrastructure
is manually hooked into powerpc architecture.

Signed-off-by: Luming Yu <luming...@shingroup.cn>
---
v0->v1: add user return notifier arch hook manually.
---
 arch/powerpc/Kconfig                    |  1 +
 arch/powerpc/include/asm/entry-common.h | 16 ++++++++++++++++
 arch/powerpc/include/asm/thread_info.h  |  2 ++
 arch/powerpc/kernel/process.c           |  2 ++
 4 files changed, 21 insertions(+)
 create mode 100644 arch/powerpc/include/asm/entry-common.h

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c10229c0243c..b968068cc04a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -277,6 +277,7 @@ config PPC
        select HAVE_STACKPROTECTOR              if PPC64 && 
$(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13)
        select HAVE_STATIC_CALL                 if PPC32
        select HAVE_SYSCALL_TRACEPOINTS
+       select HAVE_USER_RETURN_NOTIFIER
        select HAVE_VIRT_CPU_ACCOUNTING
        select HAVE_VIRT_CPU_ACCOUNTING_GEN
        select HOTPLUG_SMT                      if HOTPLUG_CPU
diff --git a/arch/powerpc/include/asm/entry-common.h 
b/arch/powerpc/include/asm/entry-common.h
new file mode 100644
index 000000000000..51f1eb767696
--- /dev/null
+++ b/arch/powerpc/include/asm/entry-common.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_POWERPC_ENTRY_COMMON_H
+#define ARCH_POWERPC_ENTRY_COMMON_H
+
+#include <linux/user-return-notifier.h>
+
+static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
+                                                 unsigned long ti_work)
+{
+       if (ti_work & _TIF_USER_RETURN_NOTIFY)
+               fire_user_return_notifiers();
+}
+
+#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
+
+#endif
diff --git a/arch/powerpc/include/asm/thread_info.h 
b/arch/powerpc/include/asm/thread_info.h
index bf5dde1a4114..47e226032f9c 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -117,6 +117,7 @@ void arch_setup_new_exec(void);
 #endif
 #define TIF_POLLING_NRFLAG     19      /* true if poll_idle() is polling 
TIF_NEED_RESCHED */
 #define TIF_32BIT              20      /* 32 bit binary */
+#define TIF_USER_RETURN_NOTIFY 21      /* notify kernel of userspace return */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE     (1<<TIF_SYSCALL_TRACE)
@@ -125,6 +126,7 @@ void arch_setup_new_exec(void);
 #define _TIF_NOTIFY_SIGNAL     (1<<TIF_NOTIFY_SIGNAL)
 #define _TIF_POLLING_NRFLAG    (1<<TIF_POLLING_NRFLAG)
 #define _TIF_32BIT             (1<<TIF_32BIT)
+#define _TIF_USER_RETURN_NOTIFY        (1<<TIF_USER_RETURN_NOTIFY)
 #define _TIF_RESTORE_TM                (1<<TIF_RESTORE_TM)
 #define _TIF_PATCH_PENDING     (1<<TIF_PATCH_PENDING)
 #define _TIF_SYSCALL_AUDIT     (1<<TIF_SYSCALL_AUDIT)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 392404688cec..70a9ea949798 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -38,6 +38,7 @@
 #include <linux/uaccess.h>
 #include <linux/pkeys.h>
 #include <linux/seq_buf.h>
+#include <linux/user-return-notifier.h>
 
 #include <asm/interrupt.h>
 #include <asm/io.h>
@@ -1386,6 +1387,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
        if (current->thread.regs)
                restore_math(current->thread.regs);
 #endif /* CONFIG_PPC_BOOK3S_64 */
+       propagate_user_return_notify(prev, new);
 
        return last;
 }
-- 
2.42.0.windows.2

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