riscv will need an implementation for exit_thread to clean up shadow stack
when thread exits. If current thread had shadow stack enabled, shadow
stack is allocated by default for any new thread.

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
---
 arch/riscv/Kconfig          | 1 +
 arch/riscv/kernel/process.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 22dc5ea4196c..808ea66b9537 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -182,6 +182,7 @@ config RISCV
 	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
+	select HAVE_EXIT_THREAD
 	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
 	select IRQ_DOMAIN
 	select IRQ_FORCED_THREADING
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index e3142d8a6e28..1f2574fb2edb 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -201,6 +201,11 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 	return 0;
 }
 
+void exit_thread(struct task_struct *tsk)
+{
+
+}
+
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
 	unsigned long clone_flags = args->flags;

-- 
2.45.0