Subject: [RFC PATCH 12/25] powerpc/exec: Set thread.regs early during exec

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Mon, 27 Apr 2020 13:34:53 +0530

In later patches during exec, we would like to access default regs.kuap to
control access to the user mapping. Having thread.regs set early makes the
code changes simpler.

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 arch/powerpc/kernel/process.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9c21288f8645..78eedf0b5c30 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1461,9 +1461,18 @@ void flush_thread(void)
 #ifdef CONFIG_PPC_BOOK3S_64
 void arch_setup_new_exec(void)
 {
-	if (radix_enabled())
-		return;
-	hash__setup_new_exec();
+	if (!radix_enabled())
+		hash__setup_new_exec();
+
+	/*
+	 * If we exec out of a kernel thread then thread.regs will not be
+	 * set.  Do it now.
+	 */
+	if (!current->thread.regs) {
+		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
+		current->thread.regs = regs - 1;
+	}
+
 }
 #endif
 
@@ -1709,15 +1718,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #endif
 #endif
 
-	/*
-	 * If we exec out of a kernel thread then thread.regs will not be
-	 * set.  Do it now.
-	 */
-	if (!current->thread.regs) {
-		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
-		current->thread.regs = regs - 1;
-	}
-
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	/*
 	 * Clear any transactional state, we're exec()ing. The cause is
-- 
2.25.3