Revert "ANDROID: Revert "arm64: move ELF_ET_DYN_BASE to 4GB / 4MB""

This reverts commit 031af365d5.

ASan can handle the new memory layout in Android P and later, which
means this change can be reverted in 4.14.

Bug: 67425063
Signed-off-by: Evgenii Stepanov <eugenis@google.com>
Change-Id: I1b09210c521ce65bbdc1e9cdaca2b5e66e097789

arch/arm64/include/asm/elf.h

@@ -173,7 +173,7 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 #ifdef CONFIG_COMPAT
 
 /* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */
-#define COMPAT_ELF_ET_DYN_BASE		(2 * TASK_SIZE_32 / 3)
+#define COMPAT_ELF_ET_DYN_BASE		0x000400000UL
 
 /* AArch32 registers. */
 #define COMPAT_ELF_NGREG		18