arm64, mm: make randomization selected by generic topdown mmap layout

[sfrench/cifs-2.6.git] / mm / util.c

diff --git a/mm/util.c b/mm/util.c
index 7922726f0a8fa7f7ef18fed3912ee48d413352ea..3ad6db9a722e07a7ff4d8805441256b7556f46f2 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -321,7 +321,15 @@ unsigned long randomize_stack_top(unsigned long stack_top)
 }
 
 #ifdef CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
-#ifdef CONFIG_ARCH_HAS_ELF_RANDOMIZE
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+       /* Is the current task 32bit ? */
+       if (!IS_ENABLED(CONFIG_64BIT) || is_compat_task())
+               return randomize_page(mm->brk, SZ_32M);
+
+       return randomize_page(mm->brk, SZ_1G);
+}
+
 unsigned long arch_mmap_rnd(void)
 {
        unsigned long rnd;
@@ -335,7 +343,6 @@ unsigned long arch_mmap_rnd(void)
 
        return rnd << PAGE_SHIFT;
 }
-#endif /* CONFIG_ARCH_HAS_ELF_RANDOMIZE */
 
 static int mmap_is_legacy(struct rlimit *rlim_stack)
 {