3 files changed, 6 insertions, 3 deletions

diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index dbded5aedb81..30277e27431a 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -101,7 +101,7 @@ static void find_start_end(unsigned long flags, unsigned long *begin,
                                 *begin = new_begin;
                 }
         } else {
-                *begin = TASK_UNMAPPED_BASE;
+                *begin = current->mm->mmap_legacy_base;
                 *end = TASK_SIZE;
         }
 }
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 845df6835f9f..5c1ae28825cd 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -112,12 +112,14 @@ static unsigned long mmap_legacy_base(void)
  */
 void arch_pick_mmap_layout(struct mm_struct *mm)
 {
+        mm->mmap_legacy_base = mmap_legacy_base();
+        mm->mmap_base = mmap_base();
+
         if (mmap_is_legacy()) {
-                mm->mmap_base = mmap_legacy_base();
+                mm->mmap_base = mm->mmap_legacy_base;
                 mm->get_unmapped_area = arch_get_unmapped_area;
                 mm->unmap_area = arch_unmap_area;
         } else {
-                mm->mmap_base = mmap_base();
                 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
                 mm->unmap_area = arch_unmap_area_topdown;
         }
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index ace9a5f01c64..4a189ba6b128 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -333,6 +333,7 @@ struct mm_struct {
         void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
 #endif
         unsigned long mmap_base;                /* base of mmap area */
+        unsigned long mmap_legacy_base;         /* base of mmap area in bottom-up allocations */
         unsigned long task_size;                /* size of task vm space */
         unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
         unsigned long free_area_cache;          /* first hole of size cached_hole_size or larger */