powerpc/exec: Set thread.regs early during exec

In later patches during exec, we would like to access default regs.amr 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@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127044424.40686-10-aneesh.kumar@linux.ibm.com

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 46a210b03d2b8029b5b297beeba50c41df563eec..de4c911d9ced3f5ac0cc39d4d28558705e138146 100644 (file)
--- 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 293d9b2ec0fa95486067d6497d3f3913d7afaf17..3f0b6adecf75a3cd761fbabdfd08df0e095f9a03 100644 (file)
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1531,14 +1531,22 @@ void flush_thread(void)
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 }
 
-#ifdef CONFIG_PPC_BOOK3S_64
 void arch_setup_new_exec(void)
 {
-       if (radix_enabled())
-               return;
-       hash__setup_new_exec();
-}
+
+#ifdef CONFIG_PPC_BOOK3S_64
+       if (!radix_enabled())
+               hash__setup_new_exec();
 #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_PPC64
 /**
@@ -1771,15 +1779,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
                preload_new_slb_context(start, sp);
 #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