[PATCH v2 1/6] mm/util: Assign a meaningful value to mmap_legacy_base

From: sxwjean
Date: Mon Oct 11 2021 - 10:34:00 EST


From: Xiongwei Song <sxwjean@xxxxxxxxx>

Let's assign a value to mmap_legacy_base in case the mmap() of some
archs needs mmap_legacy_base, like x86.

Signed-off-by: Xiongwei Song <sxwjean@xxxxxxxxx>
---
mm/util.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/util.c b/mm/util.c
index e58151a61255..40b1a8837c0b 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -414,7 +414,8 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
random_factor = arch_mmap_rnd();

if (mmap_is_legacy(rlim_stack)) {
- mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
+ mm->mmap_legacy_base = TASK_UNMAPPED_BASE + random_factor;
+ mm->mmap_base = mm->mmap_legacy_base;
mm->get_unmapped_area = arch_get_unmapped_area;
} else {
mm->mmap_base = mmap_base(random_factor, rlim_stack);
--
2.30.2