[PATCH v5 10/23] powerpc/exec: Set thread.regs early during exec

Aneesh Kumar K.V aneesh.kumar at linux.ibm.com
Thu Aug 27 14:09:18 AEST 2020


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 <aneesh.kumar at linux.ibm.com>
---
 arch/powerpc/include/asm/thread_info.h |  2 --
 arch/powerpc/kernel/process.c          | 37 +++++++++++++++++---------
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index ca6c97025704..9418dff1cfe1 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -77,10 +77,8 @@ struct thread_info {
 /* how to get the thread information struct from C */
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
-#ifdef CONFIG_PPC_BOOK3S_64
 void arch_setup_new_exec(void);
 #define arch_setup_new_exec arch_setup_new_exec
-#endif
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 016bd831908e..4633924ea77f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1494,10 +1494,32 @@ 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;
+	}
+
 }
+#else
+void arch_setup_new_exec(void)
+{
+	/*
+	 * 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
 
 #ifdef CONFIG_PPC64
@@ -1731,15 +1753,6 @@ 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
-- 
2.26.2



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