binfmt_flat: provide an asm-generic/flat.h

This file implements the flat get/put reloc helpers for architectures
that do not need to overload the relocs by simply using get_user/put_user.

Note that many nommu architectures currently use {get,put}_unaligned, which
looks a little bogus and should probably later be switched over to this
version as well.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Vladimir Murzin <[e-mail]>
Signed-off-by: Greg Ungerer <[e-mail]>

arch/arm/include/asm/Kbuild

···
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
+generic-y += flat.h
 generic-y += irq_regs.h
 generic-y += kdebug.h
 generic-y += local.h

arch/arm/include/asm/flat.h include/asm-generic/flat.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
-/*
- * arch/arm/include/asm/flat.h -- uClinux flat-format executables
- */
-
-#ifndef __ARM_FLAT_H__
-#define __ARM_FLAT_H__
+#ifndef _ASM_GENERIC_FLAT_H
+#define _ASM_GENERIC_FLAT_H
 
 #include <linux/uaccess.h>
 
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+		u32 *addr, u32 *persistent)
 {
 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 	return copy_from_user(addr, rp, 4) ? -EFAULT : 0;
···
 #endif
 }
 
-#endif /* __ARM_FLAT_H__ */
+#endif /* _ASM_GENERIC_FLAT_H */

arch/m68k/include/asm/flat.h

···
 #ifndef __M68KNOMMU_FLAT_H__
 #define __M68KNOMMU_FLAT_H__
 
-#include <linux/uaccess.h>
-
-static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
-{
-#ifdef CONFIG_CPU_HAS_NO_UNALIGNED
-	return copy_from_user(addr, rp, 4) ? -EFAULT : 0;
-#else
-	return get_user(*addr, rp);
-#endif
-}
-
-static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
-{
-#ifdef CONFIG_CPU_HAS_NO_UNALIGNED
-	return copy_to_user(rp, &addr, 4) ? -EFAULT : 0;
-#else
-	return put_user(addr, rp);
-#endif
-}
+#include <asm-generic/flat.h>
 
 #define FLAT_PLAT_INIT(regs) \
 	do { \