From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 22 Dec 2020 19:48:47 +0000 (-0500)
Subject: mm/ksm: Fix MA_STATE() init with valid mm struct
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=807830dcaa91dff52aa32c89321d97edc06248ae;p=users%2Fjedix%2Flinux-maple.git

mm/ksm: Fix MA_STATE() init with valid mm struct

The mm struct would not be initialized, fix it by moving the MA_STATE() init
to a later stage of the functions

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/mm/ksm.c b/mm/ksm.c
index defe9c3eb9a9..9aa579cef761 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -968,7 +968,6 @@ static int unmerge_and_remove_all_rmap_items(void)
 	struct mm_struct *mm;
 	struct vm_area_struct *vma;
 	int err = 0;
-	MA_STATE(mas, &mm->mm_mt, 0, 0);
 
 	spin_lock(&ksm_mmlist_lock);
 	ksm_scan.mm_slot = list_entry(ksm_mm_head.mm_list.next,
@@ -976,8 +975,9 @@ static int unmerge_and_remove_all_rmap_items(void)
 	spin_unlock(&ksm_mmlist_lock);
 
 	for (mm_slot = ksm_scan.mm_slot;
-			mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
-		mm = mm_slot->mm;
+			mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot, mm = mm_slot->mm) {
+		MA_STATE(mas, &mm->mm_mt, 0, 0);
+
 		mmap_read_lock(mm);
 		mas_set(&mas, 0);
 		mas_for_each(&mas, vma, ULONG_MAX) {
@@ -2231,7 +2231,6 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
 	struct vm_area_struct *vma;
 	struct rmap_item *rmap_item;
 	int nid;
-	MA_STATE(mas, &mm->mm_mt, 0, 0);
 
 	if (list_empty(&ksm_mm_head.mm_list))
 		return NULL;
@@ -2289,6 +2288,8 @@ next_mm:
 	}
 
 	mm = slot->mm;
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
+
 	mmap_read_lock(mm);
 	if (ksm_test_exit(mm))
 		goto no_vmas;